The authors examined impulsive suicide attempts within a population-based, case-control study of nearly lethal suicide attempts among people 13-34 years of age. Among the 153 case-subjects, 24% attempted impulsively, or within 5 minutes of their decision to attempt suicide. Relative to control subjects, male sex, fighting, & hopelessness distinguished impulsive cases. The authors suggest that inadequate control of aggressive impulses might be a greater indicator of risk for impulsive suicide attempts than depression. (24 refs)