Substance use has been identified as a significant risk factor in nonfatal and fatal suicides during adolescence. A comprehensive questionnaire on patterns of alcohol and other drug use, early childhood and nuclear family psychological and behavioral history, and previous suicidal attempts was completed by 298 (88%) of 340 outpatient adolescent substance abusers in three geographic regions east of the Mississippi River. An abbreviated Beck Depression Inventory was included to ascertain current symptoms of depressed mood. Adolescents admitting to a previous suicide attempt (30%) were compared with two age- and sex-matched samples. Substance abusers were three times as likely as a normative population of non-drug-using age- and sex-matched peers to make a suicide attempt. Thirty-three percent of attempts reported occurred prior to high school. Both the wish to hurt oneself and actual suicide attempts were found to increase significantly after the initiation of substance use. Forty percent used drugs within 8 hours before the suicide attempt, and 23% of attempters reported that their families continued to have a firearm with ammunition in the home following the suicide attempt. Adolescent substance abusers who had attempted suicide were significantly more likely than a matched group of nonattempters in the same drug treatment facility to: (1) complain of usually feeling "blue" or sad (depressed affect) during early childhood, (2) identify important childhood behavioral problems, (3) identify long-standing self-perceived impaired self-concept, and (4) identify serious parental problems, such as chronic depression or alcoholism. Self-perceived chronic loneliness in childhood appears to be a singularly important initiator of adolescent drug use and subsequent suicide attempts among drug abusers.