Rapid cycling affective disorders in the mentally retarded.

This article describes a group of 10 hospitalized, mentally retarded patients with rapid cycling affective disorders, including details of demography, pattern of illness, and response to an open trial of treatment with lithium and/or carbamazepine. Family histories of these patients revealed high rates of mental illness, including affective disorder and mental retardation. Men had an earlier onset of affective illness and rapid cycling than did women. Half of the patients showed partial or complete improvement on lithium alone or in combination with carbamazepine; those who responded to the combined treatment had more episodes of affective illness per year than those who did not. Rates of response to treatment and some clinical characteristics of these patients were similar to those of non-mentally retarded rapid cycling patients.