One hundred and twenty inmates enrolled in a comprehensive residential drug treatment program were administered the Drug Lifestyle Screening Interview (DLSI), a structured interview designed to assess the four behavioral characteristics of lifestyle drug abuse: i.e., irrespon-sibility/pseudoresponsibility, stress-coping imbalance, interpersonal triviality, and social rule breaking/bending. Subjects reporting a high volume of prior substance misuse (moderate to severe abuse of at least three different substances or severe abuse of one substance other than marijuana) recorded significantly higher scores on each of the four behavioral dimensions of lifestyle drug abuse than subjects possessing a lower volume of prior substance misuse. Furthermore, a score of 10 or higher on the DLSI cumulative index classified 76.7% of the high volume users but only 37.2% of the low volume users as lifestyle drug abusers for an overall hit rate of 71.7%.