This article explores abnormal adrenocortical function & suicidal behavior. Morning & afternoon plasma cortisols & 1-mg dexamethasone supression tests (DSTs) were performed in 65 patients with primary major depressive disorder. Recent attempters (within 28 days) were compared to previous attempters & non-attempters. Plasma cortisol levels did not differ significantly among the three groups. Nonsupression on the DST showed a relationship with other effects but not suicide attempts. (31 refs.)