Assessment of alcohol tolerance in adolescents

Objective: To improve assessment of the DSM-IV alcohol tolerance criterion in adolescents, this study tested the performance of a minimum percentage i ncrease in drinking quantity, and a proxy measure of tolerance (i.e., avera ge heavy-drinking quantity per occasion) in identifying adolescents with al cohol dependence. Method: Two adolescent samples were examined. In one samp le (N = 415, 58% male, 79% white, 57% clinical), a modified version of the SCID was used to determine DSM-IV alcohol diagnoses, and lifetime drinking history data were collected by interview. In the second sample (N = 470, 60 % male, 76% white, 100% clinical), the Adolescent Diagnostic Interview was used to determine DSM-IV alcohol diagnoses and to collect data on initial- and current- drinking quantities needed to become intoxicated. The performa nce of a percentage increase and average heavy-drinking quantity in identif ying those with dependence was evaluated using receiver operating character istic analysis. Results: The utility of a percentage increase definition wa s limited by the high degree of variability in initial-drinking quantities. Percentage increase may underassign the tolerance symptom when initial-dri nking quantities are high and overassign the symptom when initial-drinking quantities are low. Average heavy-drinking quantity per occasion, combined with a minimum frequency of drinking, demonstrated better performance than any percentage increase definition. Conclusions: Alternatives to a change-b ased (e.g., percentage increase) definition of tolerance warrant study due to Emits of change-based definitions when initial-drinking quantity shows a high degree of variability. The variability in initial-drinking quantity m ay reflect individual differences in initial sensitivity that need to be co nsidered in tolerance assessment.