The authors hypothesize obsessive-compulsive disorder carries a low risk for suicide, that suicide ideation & lifetime attempts in this disorder are due to comorbid major depressive episodes, & that patients with major depressive episodes carry the same suicidal risk as obsessive-compulsive/major depressive episode patients. 58 patients with obsessive-compulsive disorder were compared with 58 patients with obsessive-compulsive disorder with major depressive episodes & 58 with major depressive episodes. Patients with major depressive episodes & patients with obsessive-compulsive disorder with major depressive episodes displayed higher rates of suicide ideation than patients with obsessive-compulsive disorder. Lifetime suicide attempts were slightly more frequent in the patients with major depressive episodes. (23 refs.)