Multiple sclerosis and affective disorders.

Affective disorders occurring in association with multiple sclerosis have been attributed both to the psychosocial impact of a chronic disabling illness and to the structural lesions of cerebral demyelination. A review of research evidence suggests that while there is a correlation between chronic depressive symptoms and both progressive disability and lack of social support, acute major depressive and manic episodes may be psychiatric manifestations of demyelinating lesions and may be the initial presenting symptoms of multiple sclerosis. Anti-inflammatory agents may be required in the management of acute psychiatric symptoms despite the fact that these agents have a propensity to precipitate psychotic episodes. Two case reports are presented to illustrate the clinical challenge of distinguishing between organic and functional affective illness in patients with multiple sclerosis. The interplay between biological and psychological aspects of multiple sclerosis in precipitating affective disorders is discussed, with implications for patient assessment and management.