The association of specific mental disorders & comorbidity with suicide was examined using psychological autopsies & a case-control design. 75 males, aged 18-35 years, whose deaths were ruled as suicides by the coroners of Montreal & Quebec City were matched to 75 living controls. Completed suicide was found to be linked to major depression, borderline personality disorder & substance abuse. Comorbidity involving any of these disorders is frequently associated with completed suicide. (31 refs.)