Family history was examined to determine whether suicide in index patients is associated with suicidal behavior or mental disorder in their first-degree relatives. 27 suicides occurred within 5.5. years among 955 affectively disordered probands. Among 5042 proband relatives, 44 suicided prior to the study but only 1 was a relative of a proband suicide. As to attempted suicide of relatives, neither the number nor severity of attempt was predictive of suicide in probands.