The participants completed the Computerized Lifestyle Assessment Instrument as part of their assessment after admission to an institution. Their average age was 30.7 years. Results revealed that the average age at which the offenders first tried alcohol was 14. Of those who tried alcohol, 29 percent were age 12 or younger, 55 percent were ages 13-17, and 16 percent were 18 or older. A strong relationship existed between the age at which offenders first tried alcohol and the severity of their adult alcohol problems. Almost 27 percent of the offenders who tried alcohol as a preteen developed serious alcohol problems, as did 14 percent of those who first tried alcohol as a teenager. In contrast, only 5.7 percent of those who first tried alcohol as an adult subsequently developed serious alcohol problems. Similarly, approximately 64 percent of offenders who used drugs regularly as preteens developed a serious drug problem, compared with 52 percent of those who used drugs regularly as teenagers and 30 percent of those who did not begin using drugs regularly until adulthood. Overall, 15.6 percent had serious alcohol problems and 28.8 percent had serious drug problems. Findings indicated extensive and longstanding alcohol and drug problems among offenders and the higher risk among offenders first exposed to alcohol and drugs at early ages. Figures and 7 reference notes