OBJECTIVE To determine whether the rate of psychiatric disorders increases in children and adolescents with IDDM. RESEARCH DESIGN AND METHODS The rate of psychiatric disorders was assessed by highly structured interviews in a group of 93 IDDM adolescents 17–19 yr of age and compared with a healthy (nondiabetic) age-, sex-, and socioeconomic status-matched control group. RESULTS The rate of psychiatric disorders was 33.3% in the diabetic group, more than threefold higher than in the control group (9.7%). With regard to the ratepsychiatric disorders, no sex-specific differences between the two groups were found. The diabetic adolescents suffered from significantly more introversive symptoms than their healthy counterparts, especially somatic symptoms, sleeping disturbances, compulsions, and depressive moods. In spite of the elevated rate of psychiatric disorders, the rates of life events and familial adversities did not increase in the diabetic group. CONCLUSIONS The results support the notion that IDDM adolescents should be seen as a high-risk group for psychiatric disorders.