Factors associated with suicidal behavior in polydrug abusers.

In 155 polydrug abusers, drug use patterns that were associated with serious suicidal behavior included preference for depressant drugs, history of withdrawal from barbiturates, and lower frequency of PCP use. Diagnostic factors associated with increased suicidal behavior included a history of depression in the subject's mother and a diagnosis of antisocial personality in the subjects themselves. These findings are discussed in relation to Winokur's concept of broad spectrum depressive disease.