Depression Associated with Multiple Sclerosis. Looking Beyond Diagnosis to Symptom Expression

Background: While it is recognised that patients with multiple sclerosis have a high lifetime risk for major depression, less is known about sub-syndromal presentations of affective instability, i.e., irritability, sadness and tearfulness and how these symptoms of emotional dyscontrol may affect a subject's overall degree of psychological distress.

Methods: A consecutive sample of 100 out-patients with clinically definite multiple sclerosis attending their yearly neurological examination were assessed for major depression [Structured Clinical Interview for DSM-IV (SCID-1)], pathological laughing and crying [Pathological Laughing and Crying Scale (PLACS)], self report questionnaires documenting mood [Beck Depression Inventory (BDI)] and overall psychological distress [the 28 item General Health Questionnaire (GHQ)].

Results: Seventeen percent of subjects received a diagnosis of major depression, 8% had pathological laughing and crying (PLC), 48% had symptoms of emotional dyscontrol without meeting criteria for a formal psychiatric diagnosis and 27% had minimal psychiatric symptoms (emotionally stable). The groups did not differ with respect to neurological variables. However, on a validated index of psychological distress (i.e., GHQ scores > or =5), there were significantly more subjects with major depression and emotional dyscontrol than those deemed emotionally stable (P<0.0001).

Limitations: The small number of patients with PLC (N=8) curtailed statistical power when it came to analysing this sub-group.

Conclusions: Clinicians should be sensitive to complaints such as irritability and sadness in patients with multiple sclerosis, even when symptoms do not fulfil criteria for formal, psychiatric diagnoses. Our data demonstrate that such complaints are associated with levels of psychological distress that approach those experienced by patients with major depression. Given that these sub-syndromes of affective instability respond well to pharmacotherapy, detection and treatment can significantly reduce one important aspect of morbidity associated with multiple sclerosis.