Forty-one adults with established hypopituitarism and deficiency of growth hormone (GHD) were compared to an age and sex-matched group with another chronic metabolic disorder (diabetes mellitus) using standardized psychiatric rating and diagnostic measures. Nineteen (46%) of the GHD group were identified as definite psychiatric cases compared with 10 (24%) of the diabetics (odds ratio 1:9:1). The most frequent DSM III-R axis I psychiatric diagnoses were major depression (32% GHD patients and 10% of diabetic patients) and dysthymia. The risk of being a psychiatric case showed an association with duration of illness in the diabetic group, but not in the GHD group. Biochemical indices were not related to the risk of being a case in either group. Hypopituitarism is associated with a higher prevalence of psychiatric disturbance than can be attributed solely to the presence of a chronic disorder.