Mrs. S, age 50, has had relapsing-remitting multiple sclerosis (MS) for approximately 10 years. She describes her mood as “up and down” and is referred by her neurologist for psychiatric assessment of mood swings and possible depression. Fatigue limits her ability to work full-time, perform household duties, socialize with friends and family, and enjoy mental or physical exercise. In addition, her 18-year-old daughter—an important source of psychological support—is planning to leave home.
Mrs. S experienced depression 5 years ago during her divorce. She was prescribed paroxetine, 20 mg/d, and had a positive response. She took the medication for 6 months, then discontinued.
One-half of MS patients experience major depression in their lifetimes,1 and the suicide rate is approximately doubled in MS patients compared with the general population.2 Depression in MS patients often has an atypical presentation, with irritability and anger being as prominent as sadness.3 Not all emotional changes experienced by MS patients represent depressive disorders, however.
When evaluating MS patients who are struggling with depression, you can help them by diagnosing comorbid mood disorders, determining suicide risk, and providing psychological support as they cope with the impact of their illness.
MS disease course
MS is a disease of the brain and spinal cord, characterized by:
- inflammatory demyelination and gliosis
- neuronal and axonal loss
- a variety of presenting symptoms as different CNS regions are affected.
Focal areas of demyelination followed by a reactive gliosis cause white matter lesions in the brain, spinal cord, and optic nerve. Neurologic dysfunction can manifest as visual changes, spastic paresis, hypoesthesia and paresthesia, ataxia, and bowel and bladder dysfunction. MS presentation also can include optic neuritis and transverse myelitis. MS symptoms often are intensified by heat exposure.
After the initial episode, months or years may pass before additional neurologic symptoms appear. Based on its course, MS can be classified as:
- relapsing-remitting, when the disease does not progress between attacks
- secondary progressive, characterized by a gradually progressive course after an initial relapsing-remitting pattern
- primary progressive, when patients experience gradual progressive disability from symptom onset (Table 1).
Table 1
Clinical classification of multiple sclerosis (MS)
| Type | Characteristics |
|---|---|
| Relapsing-remitting* | Symptoms appear during relapses, resolve during remissions, and do not progress between relapses |
| Secondary progressive | MS symptoms that previously followed a relapsing-remitting pattern steadily become more severe and progress without relapse |
| Primary progressive | Gradual progression from symptom onset, without relapses or remission |
| Clinically isolated syndrome | A single attack that may indicate MS has occurred—such as optic neuritis or transverse myelitis—but clinical requirements for the diagnosis have not been met |
| * Patients often progress from relapsing-remitting to secondary progressive MS | |
CASE CONTINUED: Progressing symptoms
Mrs. S has had multiple MS presentations, including optic neuritis, lower extremity weakness, balance problems, and urinary incontinence. Recently, her MS symptoms have gradually progressed even in the absence of attacks, and her diagnosis has been revised to secondary progressive MS.
During psychiatric evaluation, Mrs. S denies persistent changes in sleep or appetite. She describes fatigue that starts after physical exertion and increases as the day progresses. She denies feelings of worthlessness, helplessness, excessive guilt, and suicidal ideation and does not have a history of inappropriate anger or irritability.
Diagnosing depression in MS
Normal emotional adjustment to MS can include reactions to loss of function or changes in social or occupational roles. Further, MS patients—similar to non-MS patients—experience life changes and transitions not related to the illness, such as divorce or a grown child moving away. Emotional responses to life stressors often are self-limited but may warrant an adjustment disorder diagnosis if they are associated with excessive distress or substantial impairment in social, occupational, or academic functioning (Table 2).4
Table 2
Questions to consider when assessing MS patients for depression
| Ask yourself | Reason |
|---|---|
| Are symptoms part of normal emotional changes? | Not all mood changes are pathologic or meet criteria for major depression |
| Is this an adjustment disorder? | Mood symptoms can be caused by a major stressor such as a recent diagnosis or personal loss |
| Is fatigue secondary to MS or depression? | MS typically causes fatigue after physical activity and heat exposure; fatigue early in the day points to depression |
| Are cognitive deficits related to MS or depression? | Negative thoughts point to depression whereas cognitive deficits may be caused by depression, MS, or both |
| Is this an atypical presentation? | MS patients may present with anger or irritability |
| Is this a pseudobulbar problem? | Patients with IEED might describe more concern about affect dysregulation than mood swings |
| MS: multiple sclerosis; IEED: involuntary emotional expression disorder | |
Female MS patients and those who report high stress or a family history of affective disorder may be more likely to develop clinical depression.5 Several studies have reported correlations between structural brain abnormalities and depression in MS. Feinstein et al