Depressive symptoms and severity of illness in multiple sclerosis: epidemiologic study of a large community sample.

OBJECTIVE: Previous research has shown high prevalence rates of depression in multiple sclerosis patients seen in specialty clinics. The relationships among depressive symptoms and severity, duration, and course of multiple sclerosis are controversial.
METHOD: A survey was mailed to members of the Multiple Sclerosis Association of King County (Wash.). Of the 1,374 eligible participants, 739 returned the survey, a response rate of 53.8%. Data about demographic characteristics, employment, and duration and course of multiple sclerosis were collected. Severity of multiple sclerosis was determined by the Expanded Disability Status Scale, self-report version. Severity of depressive symptoms was evaluated with the Center for Epidemiologic Studies Depression Scale (CES-D Scale). Analysis of covariance was used to compare mean CES-D Scale scores across categories of multiple sclerosis, and logistic regression was used to identify variables associated with clinically significant depression.
RESULTS: Clinically significant depressive symptoms (CES-D Scale score > or =16) were found in 41.8% of the subjects, and 29.1% of the subjects had moderate to severe depression (score > or =21). Subjects with advanced multiple sclerosis were much more likely to experience clinically significant depressive symptoms than subjects with minimal disease. Shorter duration of multiple sclerosis was associated with a greater likelihood of significant depressive symptoms, but the pattern of illness progression was not.
CONCLUSIONS: In this large community sample, the severity of multiple sclerosis was more strongly associated with depressive symptoms than was pattern of illness. Clinicians should evaluate depression in patients with recent diagnoses of multiple sclerosis, major changes in functioning, or limited social support.