Distinctions between non-suicidal and suicidal depression were investigated. Epidemiological profiles of depressed patients (40 suicidal and 40 non-suicidal) were matched for sex and age. Independent raters diagnosed each subject according to five classifications of depression. The Minnesota Multiphasic Personality Inventory (MMPI) scores for each subject were examined for any differences between the two groups. Results indicated that: (1) MMPI profiles appear to differentaite suicidal from non-suicidal depression; (2) psychiatric diagnoses are of little value in differentiating the types of depression; (3) suicidal patients are not confined to any single diagnostic group; and (4) admissions for male and female depression peak in the 20-39 year age group and then gradually decline. (Author/HLM)