The study used a standard psychological autopsy protocol to compare 140 suicide victims with 131 community controls. The risk factors for suicide among older (greater than 16 years old) and younger adolescents as well as among males and females were compared. The findings show that mood disorders, parental psychopathology, lifetime history of abuse, availability of a gun, and past suicide attempt conveyed significant risk for suicide across all four demographic groups. Psychopathology, particularly substance abuse (alone and comorbid with mood disorder), was more common and conveyed a much higher risk for suicide in the older versus younger adolescents. Younger suicide victims showed lower suicidal intent. Males chose more irreversible methods, and conduct disorder was both more prevalent and a more significant risk factor in males. The study concludes that the increased rate of suicide in older versus younger adolescents was due in part to the greater prevalence of psychopathology, namely substance abuse, and greater suicidal intent in the older population. The increased rate in males is less easily explained, but it may stem from method choice and the greater prevalence of and risk conveyed by conduct disorder in males. 5 tables and 36 references