OBJECTIVE: By means of the psychological autopsy method and a case- control design, the authors examined the association of specific mental disorders and comorbidity with suicide among young men. METHOD: Seventy- five men aged 18-35 years whose deaths were adjudicated as completed suicides by coroners of greater Montreal and Quebec City were matched to 75 living young men for age, neighborhood, marital status, and occupation. For each subject in both groups a key respondent best acquainted with the subject was interviewed by clinicians using standardized schedules. Information from the coroner and medical records was also collected. Two experienced psychiatrists, blind to outcome, established best-estimate DSM-III-R diagnoses. RESULTS: Six- month prevalence rates for all axis I diagnoses for the suicide and comparison groups were 88.0% and 37.3%, respectively; major depression was present in 38.7% and 5.3%, alcohol dependence in 24.0% and 5.3%, psychoactive substance dependence in 22.7% and 2.7%. Borderline personality disorder was identified in 28.0% and 4.0%, respectively. Of the suicide subjects, 28.0% had at least two of the following disorders: major depression, borderline personality disorder, and alcohol or drug dependence; the rate was 0.0% among the comparison subjects. CONCLUSIONS: In young men, completed suicide is linked to specific mental disorders, namely, major depression, borderline personality disorder, and substance abuse. Comorbidity involving any of these disorders is frequently associated with completed suicide.Abstract Teaser