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Cognition and mental health

MS and bipolar disorder: understanding the link

The association between multiple sclerosis (MS) and depression is well-established. Are people with MS also at risk of developing bipolar disorder?

Key points

  • Bipolar disorder is significantly more common in people with MS than in the general population.
  • This is not merely a byproduct of the stress of chronic illness; it also has to do with changes in the brain, caused by MS, that affect mood as well as physical function.
  • Mood symptoms may be caused by MS lesions, disease-related inflammation, or medications (steroids in particular).
  • Differentiating ‘primary’ (organic) mania from ‘secondary’ (MS-related) mania is crucial to ensure the correct diagnosis and treatment.
  • Key features that distinguish MS-related mania from organic mania include:
    • Late onset, often after age 35–40 years, or onset associated with MS disease progression
    • Weak or absent family history of bipolar disorder
    • Lack of response to standard treatments for bipolar disorder
  • Treatment for people with MS who experience bipolar disorder is available and effective. With coordinated care, they can successfully manage their symptoms.

MS affects movement, sensation and other bodily functions, but it also impacts the brain systems involved in thinking, emotions and behaviour. Here, I discuss the relationship between MS and bipolar disorder, a mental health condition that causes episodes of unusually high mood (mania or hypomania) and low mood (depression). Bipolar disorder has received less attention than depression in people with MS, despite its substantial effect on quality of life, treatment adherence and prognosis.

For some people with MS, symptoms of bipolar disorder appear for the first time as their disease develops. In others, existing mood symptoms may be made worse by inflammation, brain lesions or medications used to treat MS. This article explains why bipolar symptoms occur in MS, how they may present, how they can be recognised early and how they can be effectively managed.

How common is bipolar disorder in MS?

Research consistently shows that bipolar disorder is more common in people with MS than in the general population. In the general population, bipolar disorder affects roughly 1–2.4% of people. In MS, studies report current and lifetime prevalence rates of about 3% and 8%, respectively. This means people with MS have approximately double or even treble the usual risk.

Importantly, this increased risk is not simply because people with MS interact with healthcare systems more frequently than the general population, which increases the likelihood of mental health conditions being detected (we call this the ‘admission rate’ bias). Nor is it merely a byproduct of the stress of chronic illness (which might explain depression). Large studies that compare people with MS to similar individuals without MS still show a higher rate of bipolar disorder in the MS group. This suggests the association is real and probably related to changes in the brain caused by MS.

What factors cause MS-related mania?

Researchers believe there are three main mechanisms that drive cognitive and behavioural changes in MS; they can occur alone or together.

  • MS lesions that affect mood-regulating circuits
  • inflammation and immune changes
  • treatment-related factors.

Understanding these mechanisms allows clinicians to distinguish MS-related mania from ‘primary’ (organic) psychiatric illness and to deliver appropriate management.

MS lesions that affect mood-regulating circuits

This mechanism disrupts the ‘hardware’ that controls mood. MS causes inflammation and lesions (scarring) in the brain. Areas that are especially important for controlling emotions and behaviour include:

  • the right orbitofrontal cortex (OFC) – involved in regulating social behaviour, judgement and impulse control
  • the temporal lobes – important for memory and emotional processing
  • the white-matter pathways that connect these regions with deeper emotional and reward centres such as the amygdala and thalamus.

If MS lesions interfere with these circuits, the balance between emotional impulses and rational control can be disrupted. This may lead to behaviours that are characteristic of mania, including disinhibition (reduced ‘internal brakes’), uncontrolled emotions, euphoria (unusually elevated mood) and impulsivity. This pattern is sometimes called secondary mania (mania caused directly by a brain condition such as MS).

There is evidence that right-sided frontal or temporal injury leads to mania-like behaviours in other conditions (e.g. stroke, traumatic brain injury, tumours).

Understanding right- and left-sided brain functions

Consistent with literature on secondary mania from stroke or tumours, MS-associated mania is most often associated with right-sided brain lesions. The right hemisphere is dominant for processing negative emotions and withdrawal behaviours, while the left hemisphere processes positive emotions and approach behaviours. A lesion in the right hemisphere may impair the processing of negative emotions, leading to an unopposed ‘positive’ or euphoric affect (‘highs’) driven by the intact left hemisphere.

Inflammation and immune changes

During MS relapses or periods of immune activation, inflammatory molecules disrupt how brain cells communicate (think of it as a disruption to the brain’s ‘software’). One important system involved is the kynurenine pathway, which controls how the body uses tryptophan (an amino acid essential for the creation of compounds such as serotonin and melatonin).

Inflammation increases the activity of an enzyme called indoleamine 2,3-dioxygenase. This shifts tryptophan away from serotonin production towards production of quinolinic acid, a substance that overly stimulates nerve cells through NMDA receptors (N-methyl-D-aspartate receptors). This ‘excitatory overload’ can lead to symptoms like those seen in primary mania, such as agitation, mood instability, sleep disturbance and racing thoughts.

Kynurenic pathway - MS-Selfie gg1

The kynurenine pathway in inflammation-induced pathology of the central nervous system. Activation of IDO in peripheral immune cells (e.g. macrophages) or in the brain leads to production of kynurenine. This is converted to kynurenic acid in astrocytes and to quinolinic acid in microglia. Kynurenic acid can block the release of glutamate and dopamine, contributing to cognitive dysfunction. Quinolinic acid, by contrast, can increase glutamate release, which contributes to neurodegeneration. Figure modified from Haroon et al.

3-HAO, 3-hydroxy-anthranilic acid oxygenase; IDO, indoleamine-2,3-dioxygenase; KAT II, kynurenine aminotransferase II; KMO, kynurenine-3-monooxygenase; NMDA, N-methyl-D-aspartate.

This pathway is one of the clearest biochemical links between MS inflammation and bipolar-type symptoms.

Treatment-related factors

Some medications used in MS influence mood and may contribute to manic symptoms.

Steroids

High-dose intravenous methylprednisolone, typically 1000 mg/day for 3–5 days, is the most common cause of drug-induced mania in MS. Up to 12% of people treated with corticosteroids experience symptoms of mania, and nearly 65% of those with psychiatric side effects present with a mix of mania and psychosis.

A history of prior steroid-induced mood changes, female sex, older age and higher steroid doses increase risk. Steroid-induced mania typically appears 3 − 4 days after starting treatment (median 11 days in some studies) and may involve:

  • severe insomnia
  • pressured speech
  • irritability or agitation
  • grandiosity
  • psychosis in severe cases.

Symptoms usually resolve when the dose is tapered (within roughly 3 weeks), but they can persist longer in individuals with underlying bipolar disorder. I therefore try to avoid treating MS relapses with steroids. However, this is not always possible.

Other agents that may cause mania

  • Amantadine, used for fatigue, can trigger mania in susceptible individuals.
  • Modafinil and methylphenidate, also used for fatigue, have been linked to sudden switching between manic and depressive symptoms.
  • Cannabinoids may destabilise mood or cognition.
  • Interferons more commonly cause depression than mania, but irritability, aggression and mania have been reported. The risk of new psychiatric symptoms is low, and patients with stable mood disorders can usually tolerate interferons with careful monitoring.
  • Fingolimod is linked to mood changes; severe rebound inflammatory activity after discontinuation could theoretically trigger mania.

Diagnosis of MS-related mania

Distinguishing between primary bipolar disorder, secondary MS-related mania and steroid-induced mania can be difficult. Accurate diagnosis is essential for effective management, as treatment for one form may exacerbate another. Below are some of the ‘atypical’ features of MS-related mania that deviate from classic bipolar disorder.

Late onset of symptoms

Primary bipolar disorder usually begins in adolescence or early adulthood. In contrast, secondary mania associated with MS can appear later, often after age 35–40 or during disease progression. A manic or psychotic episode may sometimes be the first manifestation of MS, occurring months or years before a neurological diagnosis.

Mania coinciding with an MS relapse

A sudden change in mood, sleep or behaviour that coincides with new neurological symptoms (e.g. numbness, vision changes, weakness) may indicate that inflammation or new lesions are affecting mood circuits. There may also be evidence of disease progression from MRI scans.

Weak family history

Primary bipolar disorder often runs in families; the absence of a family history suggests a secondary cause (i.e. MS-related pathology).

Disproportionate cognitive decline

Impulse control and executive functions, such as planning, organising and paying attention, are impaired – possibly reflecting frontal lobe involvement.

Mania as an MS relapse

A minority of patients present with isolated psychiatric symptoms (mania, psychosis, delirium) as the only manifestation of a relapse. MRI often reveals new frontal or temporal lesions, even when motor or sensory signs are absent.

Lack of response to standard treatments

Failure to respond to standard mood stabilisers, or paradoxical worsening with antidepressants, warrants a re-evaluation for organic causes.

Genetic considerations

Is the risk solely environmental (inflammation/lesions), or do MS and bipolar disorder share a genetic root? The Major Histocompatibility Complex (MHC) on chromosome 6 is the primary genetic risk factor for MS (specifically the HLA-DRB1*15:01 allele). Interestingly, Genome-Wide Association Studies have suggested that the MHC region is also involved in bipolar disorder and schizophrenia.
There is some evidence that, in certain familial clusters, a gene located near the HLA locus (possibly involving the HLA-DR2 antigen) could confer susceptibility to both autoimmune demyelination and bipolar disorder. Other studies have indicated the opposite: that specific MS risk alleles in the HLA region are associated with decreased schizophrenia risk. The results are therefore mixed; some haplotypes may increase the risk of severe mental illness, while others appear protective against it. It is likely that environmental factors (inflammation, lesion burden) play a greater role than genetics in most cases.

Is the risk solely environmental (inflammation/lesions), or do MS and bipolar disorder share a genetic root? The Major Histocompatibility Complex (MHC) on chromosome 6 is the primary genetic risk factor for MS (specifically the HLA-DRB1*15:01 allele). Interestingly, Genome-Wide Association Studies have suggested that the MHC region is also involved in bipolar disorder and schizophrenia.

There is some evidence that, in certain familial clusters, a gene located near the HLA locus (possibly involving the HLA-DR2 antigen) could confer susceptibility to both autoimmune demyelination and bipolar disorder. Other studies have indicated the opposite: that specific MS risk alleles in the HLA region are associated with decreased schizophrenia risk. The results are therefore mixed; some haplotypes may increase the risk of severe mental illness, while others appear protective against it. It is likely that environmental factors (inflammation, lesion burden) play a greater role than genetics in most cases.

Management

Treatment of MS-related mania depends on the cause.

Steroid-induced mania

If steroids triggered the symptoms, the steroids should be tapered or discontinued if safe.
Short-term antipsychotic medications, such as quetiapine, olanzapine or risperidone, can help stabilise mania symptoms. Quetiapine has the added benefit of aiding sleep, which is commonly disrupted in people with MS. Use of low-dose benzodiazepines during the steroid course can help to reduce the insomnia that often precedes or triggers mania.

Mania caused by MS inflammation

If mania is part of an organic, MS relapse, treating the inflammation is important. High-dose steroids may then be necessary, even though they can in other circumstances cause mania.
This crucial distinction underscores the need for close coordination between neurology and psychiatry.

Mood swings

Lithium is still the gold standard mood stabiliser and is generally safe for psychiatric management in MS. The anticonvulsants valproate, lamotrigine and carbamazepine are useful alternatives in people with MS; they treat both the mania and other MS-related comorbidities, such as neuropathic pain and trigeminal neuralgia.

Managing future steroid treatment

People with a known history of bipolar disorder or steroid-induced instability may benefit from:

  • starting a low-dose mood stabiliser (e.g. lithium) before the steroid course
  • adding an antipsychotic temporarily (e.g. olanzapine)
  • using sleep support (e.g. low-dose benzodiazepines) to prevent insomnia (a common trigger for mania).

Long-term management

Any MS patient presenting with new-onset mania requires a comprehensive workup, including MRI (to check for new frontal/temporal lesions) and a review of recent medication changes, rather than a direct referral to psychiatry. Ongoing coordination between neurologists and psychiatrists is, however, essential. A neurologist might misinterpret mania as ‘euphoria’ related to frontal lobe damage (pseudobulbar affect), while a psychiatrist might miss the neurological signs of an MS relapse that is driving the mood change. Screening tools (e.g. Mood Disorder Questionnaire) may help identify individuals at higher risk but should not replace clinical judgement.

Recognising the distinguishing features of MS-related mania allows clinicians to intervene promptly, reduce misdiagnosis and optimise care. With integrated neurological and psychiatric management, most people with MS experiencing bipolar symptoms can achieve stable, effective control of their mood and maintain a high quality of life.

Reference

Haroon, E et al. Psychoneuroimmunology meets neuropsychopharmacology: translational implications of the impact of inflammation on behavior. Neuropsychopharmacology Rev; 2011:1–26.

Cognition and mental health

Management of mental health disorders in people with MS

Emotional problems in people with MS must be recognised, addressed and treated, rather than dismissed as an inevitable consequence of living with this chronic condition.

Key points

  • An MS diagnosis naturally triggers emotions similar to the stages of grief (denial, anger, bargaining, depression, acceptance); in addition, the unpredictability of MS causes anxiety in many patients.
  • Anxiety, often combined with depression, is linked to a poorer quality of life, cognitive dysfunction, increased risk of suicide, and significant occupational and social problems.
  • Emotional problems in MS are typically exacerbated by fatigue, pain and poor sleep – all of which interfere with therapy and lifestyle adjustments.
  • Emotional changes in MS require treatment, just as physical symptoms do. This should comprise routine screening, targeted drug treatment and structured psychological and behavioural therapies.
  • Motivational coping styles that involve direct problem-solving and active participation in treatment planning (i.e. self-management) help people with MS adjust to their diagnosis.
  • Avoidance coping strategies generally lead to poorer psychological outcomes.
  • The presence of social support is a critical protective factor.

Impact of emotional changes

Emotional disorders have an adverse effect in people with MS, potentially impairing their ability to cope with disability and reducing overall health-related quality of life. Living with MS can also adversely affect relationships, for complex reasons, including both emotional and physical problems associated with the disease. Therefore, such symptoms must be recognised, addressed and treated, rather than dismissed as an inevitable or acceptable consequence of living with a chronic condition such as MS.

Emotional disturbances in people with MS may be reactive, i.e. a natural, adaptive psychological response to being diagnosed with a long-term, unpredictable and potentially disabling disease. Common emotions include grief, sadness, worry, fear, irritability and moodiness. Elisabeth Kübler-Ross in 1969 described five common stages of grief, best known by the acronym DABDA. We have added an extra A, for Anxiety about the future, to include the emotional reaction to a diagnosis of MS. The expands the mnemonic to six stages: DABDAA.

Denial, Anger, Bargaining, Depression, Acceptance, Anxiety

These emotional stages are considered ‘normal’ and an understandable coping mechanism. As with grieving, if they are prolonged, dominant and impact your social and occupational functioning, they are considered abnormal and require intervention. Remaining angry, resentful and depressed for decades will negatively impact your functioning. 

Anxiety and depression in MS

Anxiety affects people with MS with a frequency often matching or exceeding that of depression. The highest prevalence of anxiety is observed in people with MS with low physical disability, defined by an Expanded Disability Status Scale (EDSS) score of less than 3.0. This finding suggests that anxiety is driven less by accumulated physical deficit than by the psychological factors of worry, fear and the inherent unpredictability of MS.

Maladaptive coping strategies are strongly associated with an increased risk of developing mood symptoms. A tendency to use avoidance coping – disengaging from problems rather than confronting them – is a significant predictor of poorer psychological outcomes. Similarly, psychological traits such as low optimism or a less positive attitude can heighten the risk of anxiety.

For a significant subset of patients, MS may first present not to a neurologist, but to a primary care physician, a therapist or a psychiatrist, with symptoms of anxiety or depression. Because the symptoms are psychiatric, the underlying neurological cause is not yet suspected.

Quality of life and daily functioning

Anxiety is a major contributor to the overall disease burden of MS, affecting nearly every aspect of life. Studies show that anxiety, often combined with depression, is linked to a poorer quality of life, cognitive dysfunction, increased risk of suicide, and significant occupational and social problems.

The impact of anxiety on many of the most challenging symptoms of MS – notably fatigue, pain and sleep problems – may be greater even than the effect of depression.  MS symptoms can trigger or worsen anxiety, and the resulting anxiety intensifies the perception and severity of those same symptoms, thus creating a negative feedback loop.

Damaging health behaviours linked to undiagnosed and untreated anxiety can further compromise a patient’s well-being. For example, alcohol and substance abuse, as well as smoking, not only have their own intrinsic health risks but can also interfere with MS management and adherence to treatment. 

Anxiety as a reaction to living with MS

The direct impact of the disease on the brain’s emotional circuits occurs in parallel with the profound psychological and existential challenges of living with MS. Even in the absence of any direct neurological damage to mood-regulating centres, the lived experience of MS itself provides rationale for the development of severe anxiety. 

The unpredictability of the disease and the constant knowledge that a relapse could occur at any time, potentially worsening MS symptoms and existing function, create a state of chronic hypervigilance and worry. This pervasive sense of a loss of control over one’s own body and life is a catalyst for anxiety. Anxiety creates a vicious, self-perpetuating cycle where the physical and psychiatric symptoms mutually reinforce one another.

Anxiety cycle

Multiple stressors

Beyond this overarching uncertainty, living with MS entails a host of stressors.

  • Diagnosis. The diagnostic journey is a period of intense anxiety, often involving a prolonged period of uncertainty as symptoms are investigated. Once diagnosed, patients face a continuous process of adjusting and readjusting to changing abilities.
  • Hidden problems. The invisibility of some of the most burdensome symptoms, such as debilitating fatigue, cognitive fog, or sensory disturbances, can lead to a profound sense of feeling misunderstood, isolated and frustrated.
  • Visible symptoms. Conversely, the emergence of visible symptoms, like a limp or the need for a mobility aid, can bring its own anxieties related to stigma and self-image.
  • Daily life. Financial concerns related to healthcare costs, employment and the ability to continue working, as well as the impact of MS on relationships and potential parenting, may further increase anxiety. 

Existential threat

Profound existential and symbolic threats to a person’s sense of self can further exacerbate anxiety. The sense of loss triggered by a diagnosis of MS – loss of a healthy body, a previously held future and a former identity – is followed by changes in fundamental life roles. This can lead to feelings of inadequacy, guilt and a crisis of identity – perceived as a threat to one’s core self. The constant need to adapt to new limitations can feel like a continuous erosion of the self, and the fear of future disability becomes a fear of further loss of identity.

Addressing this existential dimension of anxiety is crucial for promoting long-term psychological adjustment and overall well-being. Treatment often involves helping individuals grieve their losses, redefine their sense of self and purpose within the context of their illness, and find new sources of meaning and value in their lives. 

Cognitive impairment

The impact of anxiety on cognitive function is well documented. Cognitive impairment, particularly slowed information processing speed, is a common and debilitating feature of MS. Anxiety has a detrimental effect on cognitive domains that are already compromised, such as attention and executive functions. It does this by increasing an individual’s awareness of task-irrelevant, often threat-related, stimuli, which interferes with the goal-oriented cognitive processing required for the task at hand. Thus, the underlying cognitive deficit from MS is compounded by the cognitive interference from anxiety, leading to a greater overall level of impairment than either condition would cause alone. Importantly, therefore, treating a patient’s anxiety can lead to measurable improvements in their cognitive functioning. 

Mood, fatigue, pain and sleep – a vicious cycle

Emotional problems rarely occur in isolation in MS; they are typically part of a clinical syndrome including fatigue, pain and poor sleep. This interconnected symptom cluster reduces health-related quality of life and establishes significant barriers to therapy and lifestyle modification.

Fatigue

Fatigue is one of the most common and disabling symptoms of MS, and it is strongly and consistently correlated with anxiety. This is not a simple correlation but a predictive relationship. Higher levels of anxiety at one point in time can predict the severity of fatigue at a later date. Conversely, higher levels of fatigue can predict the later development or worsening of anxiety.

The severity of depression in highly fatigued people with MS also makes the management of fatigue a high priority in reducing the overall psychiatric burden and allowing patients to engage in psychological interventions such as cognitive behavioural therapy (CBT).

Pain and emotional distress

A two-way relationship also exists between pain and anxiety, where anxiety is associated with higher reported pain intensity and greater interference of pain with daily activities.  The pain symptoms cause distress and anxiety, and the physical and mental state of anxiety (e.g. muscle tension, worry, poor sleep) in turn exacerbates the symptoms. Moderate or severe intensity pain that interferes with work, household activities or enjoyment of life affects about one-third of people with MS.

Sleep

Sleep is probably the most neglected MS-related problem in routine clinical practice; most people with MS have a sleep disorder. Depression, anxiety, pain and many other MS-related symptoms affect sleep quality. Therefore, it is challenging to manage MS-related emotional disorders without addressing sleep quality.

Lifestyle management and adherence

The cyclical nature of this grouping of mood disorder, fatigue, pain and poor sleep creates barriers to effective management. Emotional distress and physical symptoms can hamper efforts to start or maintain a healthy lifestyle. Since modifiable lifestyle factors (e.g. exercise) are associated with reduced pain burden, a vicious cycle is established: the disease causes emotional distress, the emotional distress prevents adherence to healthy behaviours, and the lack of healthy behaviours exacerbates physical symptoms.

Inappropriate laughing and crying

Inappropriate laughing and crying (pseudobulbar affect, PBA) are two neglected symptoms that often go undetected and untreated in people with MS. This doesn’t have to be the case. They are a further sign of significant damage to the brain and yet another reason to diagnose and treat MS early and effectively.

Case study 

When I first met her, she was in her early fifties. She had had MS for over 20 years. Her family now kept her at home, isolated from the wider world. Her behaviour would embarrass them. Why?

She suffered from pathological laughter and occasionally inappropriate crying; her husband and children could not deal with this in public. She was clearly very disabled when I met her; she was unsteady on her feet and had slurred speech and dancing eyes from cerebellar problems. She had gross cognitive impairment. When I introduced myself to her, she burst into tears. Within 2−3 months of starting sertraline, a selective serotonin reuptake inhibitor (SSRI), her husband informed me that her laughing and crying episodes had improved by over 50% and the family were now taking her out regularly. He was very grateful that I had been able to educate them about her symptoms and, more importantly, help her and them as a family deal with this problem.

PBA is diagnosed using standardised scales or questionnaires, which can be self-administered (Center for Neurologic Study-Lability Scale [CNS-LS]). These symptoms respond to tricyclic and SSRI antidepressants and to a combination pill (Nuedexta®; licensed in the USA) that includes dextromethorphan hydrobromide and quinidine sulfate. 

Management of emotional disorders                                                     

Routine screening, targeted drug treatment and structured psychological and behavioural therapies are core components of integrated care in MS. Emotional changes in MS require treatment, just as physical symptoms do.

Screening and education

Routine screening for both anxiety and depression should be part of standard MS care and should be conducted at all scheduled neurological visits. You may be asked to complete different screening questionnaires for depression, anxiety, fatigue and poor sleep. Ideally these should be done before your appointment so that the healthcare professional (HCP) can act on them during the consultation. 

HCPs should educate their patients and their families about potential emotional changes associated with MS, in particular, irritability, crying and mood swings. This education should help reduce the stigma and embarrassment associated with emotional outbursts and enable the patient’s support network to develop coping strategies.

Drug treatment

Drug treatment must be tailored to the specific diagnosis and emotional disorder.

  • Depression and anxiety: The standard use of selective serotonin reuptake inhibitors (SSRIs) and serotonin−norepinephrine reuptake inhibitors (SNRIs) is recommended for the management of clinical depression and anxiety disorders.
  • Irritability: Treatment options for irritability include SSRI antidepressants, which are often needed in addition to CBT. 
  • Pseudobulbar affect (PBA): Low-dose tricyclic or SSRI antidepressants can be effective in the treatment of PBA, but their use is off-label. In the USA, the combination of dextromethorphan hydrobromide and quinidine sulfate has been approved for PBA. In other countries, the combination of these two drugs can be effective in PBA, but again, the use of these two drugs separately is off-label and not recommended.
  • Apathy: Therapeutic strategies, such as cognitive rehabilitation, that enhance cognitive processing speed and executive function are more appropriate for apathy than antidepressants. However, such approaches are hard to access on the UK NHS and are not available in many healthcare systems. There are no licensed medications for apathy, but anecdotal evidence suggests that fampridine and some stimulants may help.
  • Further research: Properly randomised controlled trials are needed to determine the effectiveness of drugs that some patients obtain and use without a prescription. These include cannabis, psychedelics and ketamine, which are currently not licensed for managing anxiety in MS and are not advised.

Psychological and behavioural interventions

Evidence-based structured psychological interventions are as important as drug treatment for the management of anxiety and depression and should be considered a first-line approach in MS. CBT can address maladaptive thought patterns (e.g. catastrophic thinking about the future) and avoidant behaviours common in anxiety. Acceptance and commitment therapy (ACT) focuses on promoting psychological flexibility and acceptance, which is crucial for managing the reactive distress, grief and fear stemming from the unpredictable nature of the disease. Mindfulness, relaxation techniques and structured exercise programs have also been shown to manage anxiety and stress effectively. 

Interventions such as physical activity and social therapies enable some people with MS to process the grief and losses imposed by MS. Simple behavioural strategies, such as taking a break from a conversation when emotions escalate, can also be beneficial. 

Protective factors

Several protective factors can bolster resilience and lower the risk of anxiety. Motivational coping styles that involve direct problem-solving and active participation in treatment planning (i.e. self-management) are associated with better adjustment. One of the most critical protective factors is the presence of social support. Robust practical and emotional help from friends and family, and the knowledge that help is available if needed, significantly reduces the risk of mood symptoms. Finding ways to continue participating in previously enjoyed activities, albeit with new limitations, are key to coping. Interventions aimed at strengthening coping skills, fostering optimism and building social support networks can play a crucial role in preventing and treating anxiety in this population.

The therapeutic challenge

There is substantial symptom overlap between anxiety and depression (e.g. sleep disturbance, fatigue, difficulty concentrating) and between these mood disorders and the primary symptoms of MS. This can make it challenging for HCPs to discern whether a specific symptom, e.g. fatigue, is primarily a neurological symptom of MS, a physical symptom of depression, a consequence of the hyperarousal and poor sleep of anxiety, or a combination of all three. Use of appropriate screening tools can help to ensure that both anxiety and depression are accurately identified and appropriately treated.

Conclusion

MS profoundly affects emotional health across a broad and complex spectrum, manifesting as major depressive disorders, high levels of anxiety, the neurological syndrome of pseudobulbar affect, the cognitive−behavioural syndrome of apathy and, rarely, mania. These emotional changes are driven by primary damage to cortical-subcortical and brainstem circuits, coupled with reactive psychological distress resulting from living with a chronic, unpredictable illness. The current standard of care mandates routine screening, targeted drug treatments and psychological support utilising CBT and ACT. 

Cognition and mental health

Mental ill-health in MS: prevalence and causes

It is now well established that the burden of MS extends far beyond the purely neurological problems to include mental health.

Key points

  • Many patients with MS experience both anxiety and depression.
  • Other emotional and behavioural changes associated with MS include cognitive changes, apathy, inappropriate laughing and crying, euphoria, mania and bipolar disorder.
  • Physical symptoms like fatigue, sleep disturbances, concentration difficulties, numbness, tingling and dizziness may occur both in MS and in anxiety states, complicating diagnosis.
  • Unless severe anxiety symptoms are formally diagnosed as an anxiety disorder, individuals miss out on targeted treatments.
  • There is growing evidence that MS-related emotional changes are not necessarily a psychological consequence of living with a disability.
    • They may have a biological origin related to structural damage in the brain, caused by the MS disease process.
    • Brain imaging techniques that measure activity reveal how these brain networks function in real time.
  • Emotional changes sometimes occur as a side effect of medications used in the management of MS, including steroids used to treat MS relapses..

Background and introduction

Multiple sclerosis (MS) is a chronic, inflammatory and neurodegenerative disease of the central nervous system (CNS) that is typically defined by its physical manifestations, such as motor weakness, sensory disturbances and fatigue. However, the burden of MS extends far beyond the purely neurological problems to include cognitive changes and mental health disorders such as anxiety, depression, apathy, mania and uncontrolled laughter and crying.

Anxiety and depression in people with MS

Among the most prevalent mental health problems in MS is anxiety, a condition that for many years was overshadowed by the clinical and research focus on depression. Anxiety is not a secondary issue but a core component of the disease experience for many people with MS. Anxiety and depression in MS are closely related, with many patients experiencing both simultaneously. Indeed, the presence of depression in people with MS is a strong predictor of the future development of anxiety, and vice versa. Both conditions share common underlying psychological risk factors such as avoidant coping styles and low optimism as well as unhealthy behaviours like smoking or lack of exercise.

Many large-scale studies have shown that anxiety is more prevalent in the MS population than in the general population. Two meta-analyses published in 2017 and 2023 assessed more than 50 published studies; based on pooled results, they estimated that 22% and 36%, respectively, of people with MS experienced anxiety.1,2 The prevalence rates for depressive disorders in people with MS are about 20−30%. Further research, utilising the UK MS Register, suggests that more than half (54%) of the 4000 patients recorded in the database have experienced clinically significant anxiety and 47% have experienced depression.3

MH anxiety

The proportions of people with different levels of anxiety (normal, mild, moderate or severe) and who have a depression score of 8 or above (N = 1961). Data from UK MS Register.3

MH depression

The proportions of people with different levels of depression (normal, mild, moderate or severe) and who have an anxiety score of 8 or above (N = 2268).  Data from UK MS Register.3

By contrast, the lifetime prevalence of any anxiety disorder in the general population in the USA is around 29% (though the prevalence at a specific point in time is lower). Anxiety is also significantly more prevalent in MS than in many other chronic neurological conditions, suggesting a relationship that may be specific to the pathophysiology or lived experience of MS.

Psychiatric symptoms versus psychiatric disorders

A critical nuance in understanding the epidemiology of anxiety in MS lies in the distinction between clinically significant anxiety symptoms and formally diagnosed anxiety disorders. The two are related but not interchangeable, and the disparity between their prevalence rates reveals a crucial aspect of the clinical challenge. The 2017 meta-analysis that found a 22% prevalence for anxiety disorders also found a substantially higher (34%) prevalence of clinically significant anxiety symptoms. This discrepancy indicates that for every ten patients who meet the formal diagnostic criteria for a specific anxiety disorder, such as generalised anxiety disorder (GAD) or panic disorder, there are approximately 15 patients who experience a level of anxiety that is severe enough to cause distress and impair functioning but is not formally identified and diagnosed in a clinical setting. The result is that these individuals miss out on targeted interventions such as specific psychotherapies or drug treatment that they might otherwise receive.

This large population of symptomatic but undiagnosed individuals may exist for several reasons. First, there is considerable symptom overlap between anxiety and MS itself. Physical symptoms like fatigue, sleep disturbances, concentration difficulties, numbness, tingling and dizziness can be manifestations of either MS or an anxiety state, creating a diagnostic challenge for clinicians and confusion for people with MS. Second, both patients and clinicians may view anxiety as an ’understandable’ or ’normal’ psychological reaction to living with a chronic, unpredictable illness, rather than as a distinct, treatable clinical entity. Finally, the historical research emphasis on depression may have led to less routine screening for anxiety in clinical practice. As an MSologist, it is also essential to differentiate formal depressive disorders from clinically significant depressive symptoms, which are much commoner than disorders.

Among those who do meet the criteria for a formal disorder, GAD appears to be the most prevalent, followed by panic disorder and obsessive-compulsive disorder. Recognising the full spectrum of anxiety, from subclinical symptoms to formal disorders, is essential for developing effective screening protocols and ensuring that all people with MS experiencing anxiety receive appropriate care (see article on management of mental ill-health in MS).

Other emotional and behavioural changes

MS impairs neuropsychiatric function (the interplay between neurological and psychological functioning) in a similar manner to its effects on other neurological functions. Living with MS can result in personality changes and subsequent relationship problems.

Cognitive changes

Cognitive impairment (i.e. dysfunction), particularly slowed information processing speed, is a common, well-documented and debilitating feature of MS. Anxiety has a demonstrably detrimental effect on cognitive domains that are often already compromised in MS, such as attention and executive functions.

Apathy

Apathy, characterised by profound loss of interest, blunted affect and reduced motivation, is also common in MS, particularly advanced MS. It is often misdiagnosed as depression. Apathy is not merely a component of low mood but is linked to executive dysfunction. Predictors identified include depressive symptoms, poor global quality of life, and poor attention and information processing speeds, probably due to MS lesions in the frontal lobe.

Inappropriate laughing and crying

Pathological laughing and crying, also known as pseudobulbar affect (PBA), are common but under-recognised and undertreated symptoms of MS that can be highly distressing and embarrassing for the patient and their relatives. The sudden, involuntary and explosive expressions of laughter or crying characteristic of PBA are often disproportionate or unrelated to the individual’s underlying emotional state.PBA is also associated with cognitive and mood problems, though the sudden and disproportionate emotional reactivity differentiates it from depression. The clinical presentation is due to frontal lobe or brainstem damage resulting from MS, which disrupts motor control pathways for emotional expression.  

Rare affective changes

Euphoria and mania are relatively uncommon in people with MS but are often triggered by high-dose steroids used to treat MS relapses.

Bipolar disorder is significantly more common in people with MS than in the general population; please see the separate post/chapter on this. The diagnosis must be made and treated by psychiatrists and involves lifelong therapy. 

The biological basis of mental illness in MS

MS-related emotional and mood changes are not necessarily a consequence of disability; they are often intrinsic to the MS disease process. This was recognised by the French neurologist Charcot, who, in 1877, noted pathological laughing, weeping, euphoria and depression in his patients who had MS.

Anxiety as a manifestation of MS pathology

While the psychological stress of living with a chronic illness contributes to anxiety in MS, there is growing evidence that anxiety is not solely a reactive or psychological phenomenon. The same autoimmune attack that damages myelin and axons, leading to physical disability, also targets and disrupts the complex neural circuits responsible for mood regulation, threat perception and emotional processing. 

Neuroinflammation and demyelination (damage to nerve insulation) are directly implicated in the development of anxiety and other psychiatric disorders. MS lesions are not confined to areas of the brain responsible for motor and sensory function but also occur within the networks that govern emotion and mood.

Structural and functional brain changes

Research has shown that people with MS can develop gradual grey matter loss in brain regions involved in emotion and motivation, particularly the limbic system and the basal ganglia. The limbic system includes the hippocampus, amygdala and cingulate cortex, and it plays a central role in processing emotions. Changes in the shape of the hippocampus have also been observed.

MH limbic system

Primary components of the limbic system. Modified from Encyclopaedia Britannica Inc.

These structural changes are thought to contribute to the development of mood and anxiety problems in MS. When MS-related inflammation, demyelination (damage to nerve insulation) or atrophy affects these areas, the brain’s ability to regulate fear and emotional responses can be disrupted. This creates a biological vulnerability to anxiety. From a structural perspective, therefore, anxiety in MS can be viewed as a direct consequence of neurological damage, in the same way that damage to the optic nerve causes visual impairment, or damage to the spinal cord leads to motor weakness.

In people with MS, depressive symptoms are consistently correlated with the volume of lesions in the brain and the degree of damage to connections between the cortex and subcortex. Neuroimaging studies show an association between depression and damage in the frontal and temporal areas of the cortex. In contrast, PBA is associated with lesions in the brainstem.

Brain imaging techniques that measure activity, such as functional MRI (fMRI), help to explain how these structural changes translate into anxiety symptoms. Rather than only showing where structural damage exists, fMRI studies reveal how brain networks function in real time. One key process identified in anxious people with MS is ‘fear overgeneralisation’. This occurs when the brain reacts to safe or neutral situations as if they were dangerous. For example, an individual learns to associate a specific signal (e.g. a picture of a circle) with a negative outcome (e.g. a mild electric shock). Anxious individuals tend to ’overgeneralise’ this fear, responding with fear to a similar but harmless signal (e.g. an oval), thus expanding their perception of danger in everyday life.

fMRI studies show that this process mainly involves the hippocampus (which is responsible for comparing incoming new experiences with ‘learned’ memories of danger) and the anterior insula (which plays a key role in generating the physical and emotional feeling of fear). In MS patients with anxiety, the physical pathways connecting these two regions are often disrupted, so that accurate information from the hippocampus is less effectively communicated to the anterior insula. As a result, the anterior insula may generate strong fear responses even when a situation is only mildly threatening or even safe.

fMRI studies have also revealed that many MS patients exhibit greater brain responses or increased recruitment of key emotional regions (e.g. prefrontal cortex and amygdala) compared to healthy controls. This likely reflects compensatory mechanisms the brain deploys to limit the clinical expression of emotional symptoms. The damaged MS brain tries to cope.

Neurological versus psychological causes

MS can trigger primary psychopathology as a result of demyelination and damage to specific functional circuits within the brain, as described above. It can be challenging to differentiate primary organic issues from reactive psychological problems, which is why people with MS may be referred for psychiatric assessments. 

I have, however, also seen patients in whom the initial symptoms were psychiatric, e.g. depression or (rarely) mania, but who were later found to have MS. The link between MS-related CNS damage and emotional symptoms is based on lesion location and lesion burden. For example, MS patients with lesions affecting the functional parts of the brain (rather than the connecting structures) exhibit a higher burden of emotional symptoms than those with lesions confined to the spinal cord. Our emotions are part of brain function in a similar way to motor function. Therefore, it is not surprising that MS impacts emotions. 

Lesion location and emotional symptoms

The evidence for a direct correlation between lesion location and anxiety is inconsistent. Some researchers suggest that, unlike depression, anxiety in MS may be driven more by psychosocial pressures and the psychological reaction to the illness rather than by focal brain damage. This discrepancy does not necessarily invalidate the biological basis of anxiety in MS. It may be that anxiety is related to more diffuse or subtle pathological changes, such as microstructural damage in white matter tracts or widespread neuroinflammation, that are not easily captured by conventional MRI lesion analysis. It is also possible that the broad distribution of the brain’s anxiety circuits means that damage to any number of different locations could produce a similar clinical outcome, making it difficult to pinpoint a single ’anxiety-causing’ lesion location. 

Other contributing factors

Emotional changes may occur as a side effect of medications used in the management of MS, including certain disease-modifying therapies. People with MS are also susceptible to the effects of the menopause, seasonal affective disorder and comorbidities associated with depression and anxiety, such as alcohol and other substance misuse disorders. It is advisable, therefore, to have a complete assessment before having a mood disorder labelled as being due to MS. 

Anxiety in MS may also be caused by high-dose corticosteroids, which are the standard treatment for MS relapses. Steroids have significant neuropsychiatric side effects, including anxiety, mania, insomnia and psychosis. For someone with MS already dealing with the stress of a relapse, the addition of steroid-induced anxiety can be particularly distressing.

‘Prodromal’ MS and psychiatric symptoms

Psychiatric comorbidities, such as anxiety and depression, have historically been viewed as consequences that follow the diagnosis of MS. Recent research, however, points to the existence of an ‘MS prodrome’, during which anxiety and depression occur years before the first classical neurological event.4 Increased rates of anxiety are a significant feature of this prodromal phase, suggesting that anxiety and/or depression may be early signs of MS, not merely a consequence. This body of recent research supports the idea that psychiatric symptoms in MS have a biological origin. This is most likely driven by the same low-level, diffuse neuroinflammatory and neurodegenerative processes that are smouldering away in the CNS long before the first eloquent MS lesion.

References

  1. Boeschoten, RE et al. Prevalence of depression and anxiety in multiple sclerosis: A systematic review and meta-analysis. J Neurol Sci 2017;372:331−341.
  2. Zhang X et al. The prevalence and risk factors of anxiety in multiple sclerosis: A systematic review and meta-analysis. Front Neurosci 2023;17:1120541.
  3. Jones KH, et al. A large-scale study of anxiety and depression in people with multiple sclerosis: a survey via the web portal of the UK MS Register. PLoS ONE 2012;7:e41910.
  4. Ruiz-Algueró, M et al. Health care use before multiple sclerosis symptom onset. JAMA Netw Open 2025;8:e2524635.
Detail, DMTsDetail, Treatment strategy

What are the attributes of the specific DMTs?

Multiple sclerosis (MS) treatment has evolved rapidly, with 11 classes of disease-modifying therapy (DMT) now available in the UK. I will summarise them briefly and explain how they fit within a treatment paradigm for effective and safe use.

Maintenance therapies versus immune reconstitution: what’s the difference?

There is a divide between the two main treatment philosophies: maintenance ̶ escalation versus immune reconstitution therapies (IRTs).

An IRT is given as a short course – a one-off treatment in the case of autologous haematopoietic stem cell transplantation (AHSCT) or intermittently for alemtuzumab, cladribine or mitoxantrone. IRTs are not given continuously, and additional courses are given only if inflammatory activity recurs. IRTs can induce long-term remission and, in some cases, potentially a cure.

Maintenance therapies, by comparison, are given continuously without an interruption in dosing (‘continuous’ administration may be daily, one or more times weekly, monthly or even once every few months). Although maintenance therapies can induce long-term remission, they cannot, by definition, result in a cure. The recurrence or continuation of inflammatory activity indicates a suboptimal response to treatment and typically requires a treatment switch. Ideally, this switch should be an escalation to a more effective class of DMT.

An article in our list of key questions, entitled How do I want my MS to be treated?, provides a more detailed comparison of maintenance and IRT therapies, including frequency of administration, efficacy, risks, use in pregnancy, vaccine response and potential for a cure.

The DMTs currently licensed in the UK (in August 2024) are listed in the table under the relevant category.

table format updated 180625 SS

Disease-modifying therapies for MS licensed in the UK. *Please note, Bonspri is available in other markets but not the UK.

How effective are the different DMTs?

The measures used to assess the effectiveness of a DMT include its ability to reduce or prevent relapses, focal inflammatory activity (that is, new or enlarging lesions) on magnetic resonance imaging (MRI), and disability progression. Additional factors that can help to assess the relative efficacy of DMTs include the proportion of clinical trial subjects who experience improvement in disability and the impact of the treatment on brain volume loss.

The MS-Selfie InfoCards are an easy-to-use resource to help people with MS compare the key features of each DMT. They contain bite-sized information designed to aid treatment choices and an overview of the key aspects of each DMT.

Efficacy of the licensed DMTs for MS can be visualised as pyramid, with the moderately effective treatments at the bottom and the more effective approaches at the top. What determines the most appropriate DMT efficacy level for an individual depends on several factors, such as baseline prognostic profile, family planning requirements, local or national treatment guidelines, socioeconomic factors, consideration of any co-existing illnesses, cognitive impairment, risk aversion and lifestyle issues.

Pyramid format updated 180625 SS

UK licensed DMTs for MS, in ascending order of efficacy.
HSCT/AHSCT, haematopoietic stem cell transplantation/autologous haematopoietic stem cell transplantation.

What is the goal of treatment? Introducing NEIDA as a target

In the past, we used no evident disease activity (NEDA) as a treatment target. ‘Disease activity’ included progression or disease worsening independent of relapse activity (termed smouldering MS). Although some of the more effective DMTs may modify this stage of the disease, many neurologists feel uncomfortable switching or stopping a DMT based simply on smouldering MS disease activity. 

Relapses and ongoing focal MRI activity are associated with a worse short-term to intermediate-term prognosis. These observations have led to the increasing adoption of ‘no evident inflammatory disease activity’ (NEIDA) as a new treatment target. For more information about treatment targets, please see the article in our key questions, Do I understand the concepts of treat-2-target and NEDA?

Many healthcare professionals (HCPs) remain sceptical of using NEIDA as a treatment target, fearing that this could lead to more people with MS being on ‘riskier’ high-efficacy therapies. However, achieving long-term remission, or NEIDA, is a well-established treatment target in other autoimmune diseases such as rheumatoid arthritis and inflammatory bowel disease. People with MS treated-to-target of NEIDA from the outset do better than those whose treatment is escalated following breakthrough disease (at a clinical or subclinical/MRI level)1. I would, therefore, strongly encourage people with MS and their HCPs to adopt NEIDA as an initial treatment target.

Flipping the pyramid

The effectiveness, or relative effectiveness, of individual DMTs becomes less critical in the context of a treatment target of NEIDA. Choosing a DMT with a lower efficacy rate simply means that a greater proportion of treated people with MS will need to be switched to higher efficacy therapies over time to achieve NEIDA. We refer to the latter of these three approaches – starting with high-efficacy treatment – as flipping the pyramid. In recent trials of alemtuzumab, ocrelizumab, ofatumumab and ublituximab, people with MS randomised to 2 years of lower efficacy DMTs (interferon-beta-1a or teriflunomide) had poorer outcomes than those receiving highly active therapy from the outset. Real-world data from registries also support this; groups of people with MS with delayed access to high-efficacy DMTs did worse than those who received high-efficacy treatments early.1,2

Horizontal versus vertical switching

If we consider the conventional step care paradigm, people with MS who switch horizontally from interferon-beta to glatiramer acetate, or vice-versa (i.e. from one moderate efficacy DMT to another moderate efficacy DMT) do less well than those who switch vertically to fingolimod, a highly effective DMT. Similarly, people with MS escalating to natalizumab, a very high-efficacy DMT, do better than those being escalated to the less effective, but still high-efficacy, DMT fingolimod. 

Continuous and intermittent immunosuppression

Another useful way of classifying DMTs is whether they are immunosuppressive, that is, they reduce the activation, or effectiveness, of the immune system. Drug regulators stipulate that a drug may be classified as immunosuppressive if it (1) causes significant lymphopaenia (low lymphocyte count) or leukopenia (low white blood cell count), (2) is associated with opportunistic infections, (3) reduces the antibody and immune response to vaccines and (4) increases the risk of secondary malignancies.

The duration and intensity of immunosuppression further determine the risks. For example, short-term or intermittent immunosuppression associated with IRTs front-loads the risks, which are substantially lower once the immune system has reconstituted itself. In comparison, long-term continuous or persistent immunosuppression, which occurs with some of the maintenance DMTs, accumulates problems over time, particularly opportunistic infections and secondary malignancies. You can read more detail on this topic in the key question How immunosuppressed am I? The following table summarises the main attributes of intermittent and persistent immunosuppression.

How immunosuppressed are you table updated format 180625 SS

The main characteristics of continuous (persistent) and short-term (intermittent) immunosuppression. Modified from Giovannoni, Curr Opin Neurol.2
AHSCT, autologous haematopoietic stem cell transplantation; PML, progressive multifocal leukoencephalopathy.

Adverse effects, monitoring and risk reduction

The complications associated with immunosuppression vary from DMT to DMT. Each individual drug summary in the DMTs section of MS-Selfie contains detailed information about the main adverse events, key monitoring requirements, use (or contraindication) during pregnancy and breastfeeding, and response to vaccines. The MS-Selfie InfoCards provide bite-sized summaries of several practical aspects, including side effects, to enable easy comparison of any treatments you are considering; some of this information is collated below for easy reference.

Short-term versus long-term adverse effects

Each drug has been given scores from 1 to 10 based on published analyses of its short-term and long-term side effects. Short-term refers to side effects that emerge when a treatment is started and decrease in severity or disappear within days or weeks. A well-known example of short-term side effects on starting interferon-beta is flu-like symptoms that typically abate within 4 ̶ 8 weeks.

A long-term side effect persists for months or doesn’t disappear on continuing the DMT. Examples include intermittent but persistent flushing after taking dimethyl fumarate, or low B lymphocyte counts with anti-CD20 therapies that may lead to low antibody or immunoglobulin levels (hypogammaglobulinaemia).

A low score denotes few or rare side effects; a high score denotes many or frequent side effects. The score does not correlate to a percentage. More information can be found in each drug summary and the manufacturer’s Summary of Product Characteristics.

Scores for short-term and long-term side effects assigned to the individual DMTs summarised in the MS-Selfie InfoCards, based on a published network meta-analysis.3
Alem, alemtuzumab; GA, glatiramer acetate; HSCT, haematopoietic stem cell transplantation; IFN-beta; interferon-beta; Nat, natalizumab.

Monitoring and risk reduction

Numerous tests are carried out at the start of treatment, and ongoing monitoring is required for many factors, to reduce the risk from adverse events. The key question, How can I reduce my chances of adverse events on specific DMTs?, explains what needs to be done at the start of DMT administration (baseline) and during subsequent monitoring. The specifics vary from DMT to DMT; please refer to the individual summaries for details such as baseline tests, follow-up, infection prevention, cancer risk, pregnancy, breastfeeding and vaccination. It is important to remember that all licensed MS DMTs have had a thorough risk ̶ benefit assessment, and their benefits are considered to outweigh the potential risks.

Administration and other practical considerations

Routes and frequency of administration

The MS-Selfie InfoCards contain a symbol for each DMT, showing how it is administered. Some DMTs are available in more than one formulation (e.g. tablets and injection). The frequency of administration varies greatly from DMT to DMT; please consult the relevant summary in the DMTs section and discuss your preferences and priorities with your MS HCP.

The route of administration for each drug in the MS-Selfie InfoCards is clearly identified by the relevant symbol. (If a DMT is available in more than one formulation, there is a separate card for each delivery route.)

Number of clinic visits

It may be important for you to consider the frequency of clinic visits. This will depend on factors such as the delivery route of your DMT, the monitoring requirements of the drug regulators and the risk of specific side effects. The table below summarises the assessments from the MS-Selfie InfoCards. This is another factor to consider in discussions with your MS HCPs about the most appropriate DMT for you.

Conclusions

People with MS must understand the objectives of MS treatments and the different treatment strategies currently available to achieve these objectives. Although the MS therapeutic landscape is complex and hence may seem overwhelming, framing the choices using a relatively simple construct should help each individual to make informed decisions about managing their MS. MS-Selfie aims to guide you in the process of deciding on the most appropriate therapeutic strategy and specific DMT for treating your disease.

References

  1. Rotstein D, et al. Association of No Evidence of Disease Activity with no long-term disability progression in multiple sclerosis: a systematic review and meta-analysis. Neurology 2022;99:e209̶ ̶ 20.
  2. Giovannoni G. Disease-modifying treatments for early and advanced multiple sclerosis: a new treatment paradigm. Curr Opin Neurol 2018;31:233 ̶ 43.
  3. Samjoo IA, et al. Efficacy classification of modern therapies in multiple sclerosis. J Comp Eff Res 2021;10:495–507.
Pregnancy and childbirth, Women's health

Planning for pregnancy

This article discusses the effects of MS on fertility, decisions about starting or stopping a DMT, the use and safety of oral contraceptives and the possible impact of in vitro fertilisation on MS disease course.

Does MS affect my fertility?

No, MS does not affect fertility. Women and men with MS are as fertile as people without MS. However, MS does not protect women and men from other causes of infertility. Fertility treatment may impact MS (see below). Please be aware that mitoxantrone, AHSCT (autologous haemopoietic stem cell treatment) and other chemotherapy treatments, such as cyclophosphamide used off-label to treat MS, may be toxic to ovarian and testicular function and require egg and sperm banking before treatment.

Should I go onto a DMT and get my MS under control before starting a family or first start my family?

In general, I recommend that women with active MS delay pregnancy until their disease is under control, optimise their general health and prepare properly for becoming a parent. There is no point in having active MS, not starting a DMT and having a catastrophic relapse in the period during which you are trying to fall pregnant.

However, a desire to start or extend your family should not change the way you want your MS managed. Early effective treatment, treating to a target of NEIDA, potentially flipping the pyramid, preventing end-organ damage and the holistic management of MS are all compatible with pregnancy. There are no rules for implementing this strategy in pregnancy because all decisions should be personalised. For example, a woman with rapidly evolving severe MS may choose natalizumab and stay on it throughout pregnancy and while breastfeeding because her MS was so active and potentially devastating. Another woman who is young, risk adverse and with a very good prognosis may choose to delay starting a DMT until she has had a child. Yet another woman, diagnosed at 40, may not want to delay falling pregnant and may opt for a DMT that is safe during pregnancy.

It is up to the person with MS, their partner and sometimes their extended family to make the final decisions about how to manage their MS during pregnancy. The healthcare professional (HCP) is there to provide information and guidance in this process.

Are oral contraceptives safe in people with MS?

To my knowledge, contraceptives are safe and effective in women with MS. The same contraindications and relative contraindications to specific contraceptives apply to women with MS as to the general population. Hormonal contraceptives are associated with an increased risk of thrombosis; women with MS who are immobile thus have a higher risk of deep vein thrombosis than those who are mobile.

Which contraceptive would you recommend?

MS should not be the deciding factor around the choice of contraceptive unless the degree of MS-related disability makes managing menstrual hygiene difficult. In this case, contraceptives that suppress menstruation have advantages, for example, continuous hormonal contraceptives or the progestin-tipped intrauterine contraceptive device (Mirena).

Inclusion criteria for participation in specific drug trials sometimes mandate double contraception, for example, a hormonal contraceptive and a barrier method. This is to try and avoid accidental pregnancies while taking an investigational compound without a safety track record in humans.

How long before I fall pregnant must I stop my DMT?

It depends on which DMT you are taking. Only the DMTs that are teratogenic or potentially teratogenic (i.e., may cause foetal malformations) need to be stopped before you fall pregnant. It is essential to allow sufficient time for these agents to be eliminated from the body.

Teriflunomide

Teriflunomide has the potential to cause birth defects; therefore, patients must have effective contraception whilst on this treatment. It has a very long half-life because it is reabsorbed in the intestine and is eliminated slowly from the plasma. Without an accelerated elimination procedure, it takes up to 8 months to reach plasma concentrations of less than 0.02 mg/l, which are considered safe. Remarkably, due to individual variations in teriflunomide clearance, it may take up to 2 years to fall to acceptable levels. An accelerated elimination procedure with cholestyramine or activated charcoal can be used at any time after the discontinuation of teriflunomide.

Teriflunomide accelerated elimination procedure

After stopping treatment with teriflunomide:

• Cholestyramine 8 g is administered three times daily for 11 days, or cholestyramine 4 g three times a day can be used if cholestyramine 8 g three times a day is not well tolerated.

• Alternatively, 50 g of activated powdered charcoal is administered every 12 hours for 11 days.

Following either of the accelerated elimination procedures, it is recommended to verify elimination by checking teriflunomide blood levels and allow a waiting period of 1.5 months between the first occurrence of a plasma concentration below 0.02 mg/l and planned fertilisation.

S1P modulators

S1P modulators are contraindicated during pregnancy, owing to the risk to the foetus. Before starting treatment in women of childbearing potential, we do a urine pregnancy test. Women taking an S1P modulator must use effective contraception during treatment and then continue for:

  • 2 months after stopping treatment with fingolimod (Gilenya)
  • 10 days after stopping treatment with siponimod (Mayzent)
  • 3 months after stopping treatment with ozanimod (Zeposia)
  • 7 days after stopping treatment with ponesimod (Ponvory).

Stopping the S1P modulators brings the potential for rebound disease activity, so most neurologists now prefer to transition women on one of these therapies to another class of DMT that is considered safer in pregnancy.

Safer options

Safer options during pregnancy include an injectable (interferon-beta or glatiramer acetate), a fumarate, an anti-CD20 therapy, natalizumab or an immune reconstitution therapy (cladribine or alemtuzumab). I cover some of the issues related to anti-CD20 therapies in the MS-Selfie case study ‘Wait to fall pregnant or start a DMT now?’.

The good news is that several DMT options are now available to women with MS wanting to fall pregnant.

Can I have IVF, and what will IVF do to my MS?

There is no reason why a person with MS cannot have IVF (in vitro fertilisation). However, there appears to be a slightly increased risk of relapse after IVF and egg harvesting. Whether this is due to stopping DMTs before undergoing IVF or due to the drugs used to stimulate ovulation is unknown. Studies reporting an increase in disease activity after IVF are more likely to be published than studies not showing such an increase so that publication bias may affect the findings. I recommend viewing IVF as a planned pregnancy and giving women with MS the option of receiving a DMT that is relatively safe in pregnancy or treating their MS with immune reconstitution therapy before IVF.

References

Krysko KM et al. Treatment of women with multiple sclerosis planning pregnancy. Curr Treat Options Neurol 2021;23:11.

Other articles in this series on Pregnancy and childbirth:
Managing MS during pregnancy
Preparing to give birth
Breastfeeding if you are on a DMT
Concerns about parenting

DMTs, Treatment strategy

How immunosuppressed am I?

Do you understand the difference between short-term intermittent and long-term continuous immunosuppression? Here we address another of the key questions to consider before deciding on a specific disease-modifying therapy (DMT).

Key points

  • Immunosuppressive disease-modifying therapies (DMTs) reduce the immune system’s effectiveness.
  • It is important to weigh up the benefits and risks of short-term versus continuous immunosuppression.
  • Non-selective DMTs suppress the adaptive and innate immune systems; selective DMTs do not affect the innate immune system and are thus associated with a low risk of bacterial infections.
  • The implications of immunosuppression need to be considered within the context of other health and lifestyle factors.

Which DMTs cause immunosuppression?

A useful way of thinking about DMTs is based on whether they are immunosuppressive. Broadly speaking, an immunosuppressive is any DMT that reduces the immune system’s activation or effectiveness. 

From a regulatory perspective, for a drug to be classified as immunosuppressive, it should: 

  • cause significant lymphopaenia or leukopenia (reduced white cell counts)
  • be associated with opportunistic infections (infections that don’t occur in people with a normal, healthy immune system)
  • reduce antibody and/or T-cell responses to vaccines 
  • increase the risk of secondary malignancies. 

Based on the above criteria, the interferon-beta preparations and glatiramer acetate are immunomodulatory rather than immunosuppressive. Teriflunomide is also an immunomodulatory therapy with the potential, albeit small, to cause immunosuppression. In real life, however, very few people with MS treated with teriflunomide develop significant lymphopaenia or leukopenia; if they do, we tend to stop the drug. The other licensed DMTs are immunosuppressive to a greater or lesser degree. 

Short-term versus continuous immunosuppression

The duration and intensity of immunosuppression further determine the risks. Short-term or intermittent immunosuppression associated with an immune reconstitution therapy (IRT) front-loads the risks, which decrease substantially once the immune system has reconstituted itself. In comparison, long-term continuous or persistent immunosuppression, which occurs with most maintenance DMTs, accumulates problems over time, particularly opportunistic infections and secondary malignancies.

Live vaccines are, in general, contraindicated in patients on continuous immunosuppressive therapies. However, someone with MS on an IRT who has reconstituted their immune system can tolerate and respond to live vaccines. The benefits of administering live vaccines always need to be balanced against the risks of the vaccine.

How immunosuppressed are you table updated format 180625 SS

The main characteristics of continuous persistent and short-term (intermittent) immunosuppression. Modified from Giovannoni, Curr Opin Neurol.1
AHSCT, autologous haematopoietic stem cell transplantation; PML, progressive multifocal leukoencephalopathy.

Selective versus non-selective immunosuppression

Immunosuppression that accompanies DMTs may be selective or non-selective. Non-selective therapies deplete and/or suppress both the adaptive immune system (T cells and B cells) and the innate immune system (monocytes, neutrophils and natural killer [NK] cells). Alemtuzumab, AHSCT (autologous haematopoietic stem cell transplantation) and mitoxantrone are non-selective and are therefore associated with acute bacterial infections such as listeriosis, nocardiosis and cytomegalovirus reactivation. In comparison, anti-CD20 agents (ocrelizumab and ofatumumab) and cladribine are selective, do not affect the innate immune system and are therefore associated with a low risk of acute bacterial infections. 

How immunosuppressed are you_MET vs IRT_2 Dec 2024

Classification of disease-modifying therapies for relapsing forms of MS. Modified from Giovannoni, Curr Opin Neurol.1
AHSCT, autologous haematopoietic stem cell transplantation.

Other considerations

Please note that the implications of immunosuppression are not black and white but interact with other factors such as:

These factors have been highlighted during the COVID-19 pandemic, particularly in relation to the risk of severe COVID-19 and the variations in vaccine responses among people with MS (including waning of the immune response).

It is important to realise that we can derisk (reduce the risk of) some complications associated with long-term immunosuppression and the use of DMTs. Please see the post entitled How can I reduce my chances of adverse events on specific DMTs?

References

  1. Giovannoni G. Disease-modifying treatments for early and advanced multiple sclerosis: a new treatment paradigm. Curr Opin Neurol 2018;31:233 ̶ 43.
Causes and prevention of MS

What is multiple sclerosis?

This is the first of a series of basic lessons to help you understand multiple sclerosis (MS).

Key points

  • MS is an autoimmune disease in which the immune system attacks the central nervous system.
  • Its exact cause is unknown; some contributory environmental factors are outlined.
  • Common manifestations of MS include lesions, relapses and intermittent symptoms, which often worsen with fatigue.
  • Early treatment is important to help prevent the damage that occurs with MS.

Multiple sclerosis (MS) is an organ-specific autoimmune disease. Autoimmune simply means that the immune system, whose primary role is to fight infections and cancers, goes awry and attacks itself. Organ-specific means that a disease is limited to one organ. So, in the case of MS, the immune system attacks the central nervous system (CNS), which consists of the brain, spinal cord and optic nerves.

Every organ in the body has its specific autoimmune disease. For example:

  • joints: rheumatoid arthritis
  • skin: psoriasis 
  • insulin-producing cells of the pancreas: type 1 diabetes
  • intestines: inflammatory bowel disease
  • kidneys: autoimmune nephritis (interstitial or glomerulonephritis).

The cause of MS

At present, the exact cause of MS is unproven. MS is a complex disease that occurs due to the environment’s interaction with inherited or genetic factors.1 Some of the main environmental factors are:

  • low vitamin D levels or a lack of sunshine
  • smoking 
  • Epstein–Barr virus (EBV), the virus that causes infectious mononucleosis (glandular fever) 
  • obesity, particularly in adolescence.

What we don’t know is how these genetic and environmental factors interact to cause MS. There are many genetic variants that predispose someone to get MS, but only a minority of people who have these variants will get the disease. Similarly, only a minority of people exposed to environmental risk factors get the disease.

Mechanisms that underlie the common manifestations of MS

Lesions

MS is characterised by inflammatory lesions – areas of damage or scarring (sclerosis) in the CNS – that come and go. The clinical manifestations of MS depend on where these inflammatory lesions occur. If, for example, a lesion involves the optic nerve, it will cause impaired vision; if it involves the brain stem, it causes double vision, vertigo or unsteadiness of gait; a spinal cord lesion leads to loss of feeling, limb weakness or bladder and bowel problems.  

Relapses

A new MS lesion in a site that is eloquent will cause symptoms and neurological signs; if these last for at least a day, they are called an attack or a relapse. If a lesion occurs in a site not associated with overt symptoms, this is often referred to as a subclinical or asymptomatic relapse. Subclinical relapses can be detected using magnetic resonance imaging (MRI). It is said that for every clinical attack there are 10 or more sub-clinical attacks (new MRI lesions).2 

Damage frequently occurs at the site of MS lesions. The inflammation strips the myelin covering the nerve processes and may cut through axons. Axons are the nerve processes that transmit electrical impulses or signals. When the axons are stripped of their myelin sheath, and/or are cut, they can’t transmit electrical signals. This causes loss of function, which manifests with specific symptoms.

Demyelination: loss of the myelin sheath that insulates nerves, leading to disruption of electrical signals. Image courtesy of Timonina/shutterstock.com. 

Intermittent symptoms

Surviving axons that pass through the lesion are able to recover function, by synthesising and distributing so-called ion channels across the demyelinated segment or by being remyelinated. Both these processes are not perfect. For example, the new sodium channels may not function normally, so they sometimes fire spontaneously. The spontaneous firing of axons may cause positive symptoms, for example, pins and needles, pain or spasms. The new myelin is typically thinner and shorter than normal and is temperature, fatigue and stretch sensitive. 

Stretch sensitivity

If someone with MS has a lesion in their spinal cord, electric shock-like sensations may occur when they stretch the spinal cord by bending or flexing their neck; this is known as Lhermitte’s sign.  

Temperature sensitivity

Recurrent symptoms may occur when body temperature rises, for example following fever, exercise or a hot bath. The MS symptoms (which may vary among individuals) disappear when the fever resolves or the body cools down. The temperature sensitivity is often referred to as Uhtoff’s phenomenon. 

Fatigue

Symptoms tend to worsen with physical and/or mental fatigue; for example, someone with MS may begin dragging a leg or dropping their foot after 20–30 minutes of walking. This is because the transmission in the functioning nerves, which have been previously damaged, begins to fail. This failure may be related to a lack of energy and/or to temperature changes that occur with exercise. 

Worsening MS (also called progressive MS)

If the axons, or nerve processes, above and below an MS lesion die off, the surviving axons may sprout to take over the function of the axons below the lesion. This puts an unnecessary strain on the surviving axons, which makes them vulnerable to die off in the future. A reduction in the number of nerves in a neuronal system reduces the neurological reserve of that system, making it more vulnerable to future attacks. In other words, the ability to recover from future attacks is reduced, and the neuronal pathway is susceptible to delayed degeneration and premature ageing. Clearly, if no treatment is given and focal inflammatory lesions continue to come and go, this will cause worsening of the disease. If enough damage is allowed to accrue, even switching off new inflammatory lesions may not prevent the so-called delayed neurodegeneration. This is why one of the primary principles of managing MS is early treatment to prevent damage from occurring in the first place. We have also discovered that the neuronal systems with the longest nerve fibres, in particular the bladder and legs, are much more susceptible to damage. We think this is simply because the longest pathways provide the greatest scope to be hit by multiple MS lesions.

Ageing and MS

As we get older our nervous systems degenerate. If we live long enough, we will all develop age-related neurological problems, such as unsteadiness of gait, loss of memory, reduced vision, loss of hearing, and poor coordination. 

What protects people with MS from becoming disabled and developing age-related neurodegeneration are brain reserve and cognitive reserve. Brain reserve is simply the size of your brain or the number of nerve cells you have. Cognitive reserve, in comparison, relates to how well these nerves function; it is associated with your level of education and how well you enrich your life by using your brain. From about 35 years of age, our brains start to shrink. In MS, this brain shrinkage is in general much greater than normal, and the resulting reduction in brain and cognitive reserve almost certainly primes the nervous system to age earlier. This is one of the reasons why people with MS continue to develop worsening disability later in the course of their disease. This insight is one of the main reasons why we promote early effective treatment of MS to protect and maintain brain and cognitive reserves.  

References

  1. Olsson T, et al. Interactions between genetic, lifestyle and environmental risk factors for multiple sclerosis. Nat Rev Neurol 2017;13:25–36.
  2. Gafson A, et al. The diagnostic criteria for multiple sclerosis: From Charcot to McDonald. Mult Scler Relat Disord 2012;1:9–14

Brain health and holistic management of MS, Treatment strategy

What are the consequences of not treating MS?

Are there valid reasons not to treat MS with a disease-modifying therapy? What are the consequences of not treating MS? Is watchful waiting justified?

Key points

  • Untreated MS will, given time, result in physical disability, impaired quality of life and ‘hidden’ problems such as cognitive impairment, anxiety and depression.
  • Brain atrophy, or shrinkage, occurs at a faster rate in people with MS than in healthy individuals.
  • Optic neuritis, inflammation or destruction of nerve fibres in the brain and spinal cord, and extensive damage to the cerebral cortex (grey matter) are some consequences of MS lesion development.
  • Quality of life impacts may include reduced mobility, relationship difficulties, increased likelihood of unemployment and memory impairment.
  • Without treatment, the life expectancy of people with MS is reduced by about 6 ̶ 8 years.
  • There are, however, several valid reasons why some people with MS prefer not to receive disease-modifying treatments.

Risks from no disease-modifying treatment

Many patients ask me what will happen to their MS if they don’t take a disease-modifying treatment (DMT) and how effective DMTs are at preventing negative outcomes. Here I try and address questions you need to ask yourself before starting a DMT.

If you are an individual with MS, predicting your disease course is difficult. However, many studies monitoring groups of people with MS show patterns in relation to the progression of the disease and its outcome, with various data sets being consistent.

Given sufficient time, most people with MS who are not treated will become disabled. Most people focus on physical disability, but MS causes many hidden problems, such as cognitive impairment, anxiety and depression.

How untreated MS can progress – headline results

The slides below summarise some of the outcomes of untreated MS; these include brain changes (atrophy), further MS lesion development, reduced health-related quality of life, long-term impact on physical and mental health and shorter life expectancy. (To enlarge an individual slide, click on the arrow at the top right.)

Brain changes
MS lesion development
Quality of life impact
Long-term outlook

DMTs have changed the landscape

It is important to note that these outcomes are from the pre-DMT era and don’t apply to populations of people with MS treated with DMTs. New real-life data indicate that DMTs, particularly high-efficacy DMTs, are preventing many of these problems. By not being on a DMT, if you have active MS, you are at risk of acquiring damage from focal inflammatory lesions. Early in the disease course, you may not be aware of this damage because of the remarkable capacity of the nervous system to compensate for damage (neurological reserve). However, once the compensatory mechanisms have been exhausted, further damage results in overt disability. It is important to regard DMTs as preventive treatments, i.e. their aim is to delay, and hopefully prevent, future disability.

Possible reasons for not receiving a DMT

Many people with MS will not be on a DMT, for a variety of reasons. The list below is probably not extensive; if you know of other reasons why someone who qualifies is not taking a DMT, please let me know.

Inactive MS

Someone with inactive MS will not be eligible for a DMT. There is no standard definition of active MS. To me, active MS is recent evidence of focal inflammatory disease activity, defined as:

  • clinical relapse(s) in the last 2 years
  • OR magnetic resonance imaging (MRI) activity in the last 12 ̶ 36 months (new or enlarging T2 lesions or T1 Gd-enhancing lesions)
  • OR a raised cerebrospinal fluid (CSF) neurofilament light chain level in the last 12 months.

Worsening disability in MS without focal inflammatory disease activity is not active disease. It can be due to damage caused by past inflammation, smouldering MS or the effects of premature ageing; anti-inflammatory DMTs can’t address this problem. We need different types of DMTs to address these mechanisms – for example, neuroprotective and/or remyelination therapies and anti-ageing therapies.

Watchful waiting

In many situations, some neurologists think someone with MS will end up having benign disease, so they are not prepared to start treatment until the patient develops some overt disability. I abhor this practice and it is one of the reasons I spend so much of my time disseminating knowledge and getting involved with health politics. Watchful waiting, in terms of treating MS, is not supported by data. The earlier and more effectively you treat MS, the better the outcome. The only situation I could condone watchful waiting in someone with active MS is when the diagnosis of MS is in question. Sometimes in neurology, time is the best diagnostician. If the person has MS, it will declare itself with further disease activity, and this would be the trigger to start a DMT.

Family planning

Trying to fall pregnant, pregnancy or breastfeeding are common reasons to interrupt or stop DMTs. Please note that most neurologists now have options to treat MS during pregnancy and while breastfeeding, so this is becoming a less common reason for not taking a DMT.

Risk aversion

Some people with MS are not prepared to take the potential risks associated with DMTs.

Personal reasons

Some people with MS don’t believe in having their MS treated, preferring to try alternative medicines and turn down traditional DMTs. If you are one of these people, I would recommend you continue to interact with your MS team and have regular monitoring of your MS (clinical, MRI, patient-related outcome measures [PROMS] and possibly CSF analyses). Then, if these alternative strategies don’t work, you will keep open the option of treatment with a ‘traditional DMT‘. Most alternative treatment strategies for MS are compatible with DMTs and hence should be viewed as complementary. Understanding the difference between complementary and alternative treatments is important. Complementary treatment strategies are part of the holistic management of MS.

Financial constraints

In some parts of the world, MS treatment is not covered by a national health service or medical insurance scheme and some people with MS simply can’t afford DMTs. Even in rich countries, people with MS who are disenfranchised don’t have access to treatment; these may include illegal immigrants, refugees and asylum seekers waiting for their applications to be processed.

Progressive or more advanced MS

In most countries, neurologists don’t initiate treatment in patients with more advanced MS. This approach is based on a lack of evidence of the effectiveness of DMTs in this population. However, we are increasingly offering ocrelizumab (for active primary progressive MS), siponimod (for active secondary progressive MS) or off-label therapies on a compassionate basis to people with more advanced MS. In addition, there is also the potential to participate in clinical trials of new treatments for more advanced MS.

Ageism

Some healthcare systems and some neurologists are reluctant to start DMTs in people with MS who are over a certain age. This is based on a lack of evidence of the effectiveness of DMTs in this population, and it is why we need to do clinical trials in older people with MS.

Comorbidities

Many people have other medical problems for which the treatment takes priority over the treatment of MS. For example, a patient of mine was diagnosed with stage four bowel cancer. After her surgery, she started an intensive period of chemotherapy during which we stopped her DMT.

References

  1. Fisher E, et al. Gray matter atrophy in multiple sclerosis: a longitudinal study. Ann Neurol 2008;64:255–65.
  2. Barkhof F, et al. Imaging outcomes for neuroprotection and repair in multiple sclerosis trials. Nat Rev Neurol 2009;5:256–66.
  3. Simon JH. Brain atrophy in multiple sclerosis: what we know and would like to know. Mult Scler 2006;12:679–87.
  4. Ziemssen T, et al. Optimizing treatment success in multiple sclerosis. J Neurol 2016;263:1053–65.
  5. Hickman SJ, et al. Detection of optic nerve atrophy following a single episode of unilateral optic neuritis by MRI using a fat-saturated short-echo fast FLAIR sequence. Neuroradiology 2001;43:123–8.
  6. Trapp BD, et al. Axonal transection in the lesions of multiple sclerosis. N Engl J Med 1998;338:278–85.
  7. Peterson JW, et al. Transected neurites, apoptotic neurons, and reduced inflammation in cortical multiple sclerosis lesions. Ann Neurol 2001;50:389–400.
  8. Orme M, et al. The effect of disease, functional status, and relapses on the utility of people with multiple sclerosis in the UK. Value Health 2007;10:54–60.
  9. Pfleger CC, et al. Social consequences of multiple sclerosis (1): early pension and temporary unemployment – a historical prospective cohort study. Mult Scler 2010;16:121–6.
  10. Kobelt G, et al. Costs and quality of life of patients with multiple sclerosis in Europe. J Neurol Neurosurg Psychiatry 2006;77:918–26.
  11. Feuillet L, et al. Early cognitive impairment in patients with clinically isolated syndrome suggestive of multiple sclerosis. Mult Scler 2007;13:124–7. 
  12. Confavreux C and Compston A. Chapter 4. The natural history of multiple sclerosis. In: McAlpine’s Multiple Sclerosis, Fourth Edition, 2006; 183 ̶ 272. Churchill Livingstone.
  13. Weinshenker BG et al. The natural history of multiple sclerosis: a geographically based study. I. Clinical course and disability. Brain 1989;112:133 ̶ 46.
  14. Torkildsen GN, et al. Survival and cause of death in multiple sclerosis: results from a 50-year follow-up in Western Norway. Mult Scler 2008;14:1191–8.
  15. Kingwell E, et al. Relative mortality and survival in multiple sclerosis: findings from British Columbia, Canada. J Neurol Neurosurg Psychiatry 2012;83:61–6.
  16. Sadovnick AD, et al. Cause of death in patients attending multiple sclerosis clinics. Neurology 1991;41:1193–6.
  17. Brenner P, et al. Multiple sclerosis and risk of attempted and completed suicide – a cohort study. Eur J Neurol 2016;23:1329–36. 

Stages of MS

What type of MS do I have?

MS has historically been classified into different subtypes, and this subdivision dictates what treatments you are eligible for. These MS disease subtypes are not supported biologically, however, and many MS neurologists are of the opinion that MS is one disease.1

Key points

  • The difference between relapsing MS and non-relapsing progressive MS is explained.
  • The stages of MS have different labels, for historical development and reimbursement reasons, but biologically MS is one disease.
  • From a treatment perspective, the key thing is to know if your MS is active or inactive.
  • Active MS can be differentiated from inactive MS by relapses, MRI evidence of disease activity and raised neurofilament levels in the cerebrospinal fluid.

Type of MS

You should be able to classify yourself as having either relapsing MS or non-relapsing progressive MS. Knowing what type of MS has been diagnosed and whether your MS is active or inactive will allow you to ask your MS neurologist questions about the MS treatments available to you. 

Around 85–90% of people with MS start with so-called relapse-onset MS, i.e. they have a definite attack of symptoms that is usually followed by a period of complete or incomplete recovery. A single attack may be labelled as a clinically isolated syndrome (CIS): it does not fulfil the current diagnostic criteria for full-blown MS, but it means someone is at risk of further attacks and hence of developing MS in the future.

EDSS, Expanded Disability Status Scale score
EDSS, Expanded Disability Status Scale score

Once you have more attacks, either clinically in the form of relapse or subclinically with new lesions on magnetic resonance imaging (MRI), then you are usually diagnosed as having MS. The diagram below illustrates the typical course of repeated relapses and remissions, with worsening disability over time, that characterises so-called relapsing–remitting MS (RRMS).

After a variable period, people with relapse-onset MS may notice worsening neurological function without improvement. This is called secondary progressive MS (SPMS) and it can occur with superimposed relapses (so-called relapsing SPMS [RSPMS]) or without relapses.

EDSS, Expanded Disability Status Scale score
EDSS, Expanded Disability Status Scale score

A small number of people with MS (10–15%) will present with worsening neurological function without a prior history of relapses; this is called primary progressive MS (PPMS).

Interestingly, some people with PPMS go on to have relapses, and this is referred to as progressive relapsing MS (PRMS).

EDSS, Expanded Disability Status Scale score
EDSS, Expanded Disability Status Scale score

Rarely, someone may present with worsening neurological function, similar to PPMS, but have a prior history of just one relapse. This is referred to as single-attack progressive MS (SAP), but most MS specialists classify these patients as having SPMS. 

In summary …

  • Relapsing MS captures all people with MS who are still having relapses, i.e. within the last 2 years, and includes RRMS, RSPMS and PRMS.
  • Non-relapsing progressive MS refers to SPMS and PPMS: these latter two groups should have no history of recent relapses, i.e. in the last 2 years.

To further confuse things, non-relapsing progressive MS used to be referred to as chronic progressive MS (see below). 

Why is this important?

Different DMTs are licensed for different types of MS, and many treatment guidelines specifically state the type of MS for which a particular drug can be used.

Is MS one or more diseases?

In the past, MS was regarded as one disease: either you had MS, or you did not. The stages were referred to as early relapsing MS or chronic progressive MS, but MS was still one disease. 

When disease-modifying therapies (DMTs) were developed, MS was split into multiple sub-types. This categorisation was driven by commercial considerations, and it allowed interferon-beta to be licensed in the US under the Orphan Drug Act. The classification of orphan disease in the US requires there to be fewer than 200,000 people with that diagnosis. Dividing MS into RRMS, SPMS, PPMS and later CIS ensured that each category met this criterion. 

Since then, PRMS and radiologically isolated syndrome (RIS) have been added as potential subtypes. These classifications tend to be arbitrary and overlap, but there is no biological basis to support MS being more than one disease. 

Is your MS active or inactive?

From a treatment perspective, it is important to know if your disease is active or inactive. In active MS, there is evidence of ongoing inflammation in the brain and spinal cord. If you are having relapses, are developing new lesions on MRI or have raised neurofilament (NFL) levels in your cerebrospinal fluid (CSF) or blood, your MS is active. 

Active MS responds to anti-inflammatory treatments; inactive MS is less responsive to currently licensed DMTs. 

Criteria for ‘active’ MS accepted by many MS health professionals. CSF, cerebrospinal fluid; NFL, neurofilament light.
*Some neurologists accept 24 months, 36 months or even longer when assessing MRI activity. There is no international consensus on the gap between the baseline and new MRI scan to define active disease.

The term progressive MS refers to the stage of MS when your disability gets worse – independent of relapses, and possibly of focal inflammatory lesions. I say ‘possibly’, because our current MRI scans don’t show new or enlarging microscopic lesions but only those that are larger than ~3–4 mm. NFL measurements in either the CSF or blood have the advantage of being additive and integrating inflammatory activity. In my experience, about one in ten patients classified as ‘inactive’ based on clinical and MRI activity is found to have active MS when CSF NFL levels are analysed. Unfortunately, however, many MS neurologists, regulators and payers do not accept this latest definition of MS disease activity because tests for NFL levels are currently not widely available. 

In conclusion, knowing the type of MS you have and whether your disease is active or inactive will allow you to discuss with your MS specialist the kinds of treatment available to you. 

References

Giovannoni G, et al. Smouldering multiple sclerosis: the ‘real MS’. Ther Adv Neurol Disord 2022;15:17562864211066751.