Abstract
The Millon Clinical Multiaxial Inventory (MCMI versions I, II, and III) includes a scale to assess drug use problems, Scale T-Drug Dependence. Detailed drug use data from a sample of 659 known drug users along with MCMI-II results were examined to determine the operating characteristics of the MCMI-II drug dependence scale. Operating characteristics, sensitivity, specificity, positive predictive power, negative predictive power, and overall diagnostic power were calculated for base rate cutoffs and for the number of prototypic items endorsed to determine the diagnostic efficiency of Scale T-Drug Dependence in identifying regular drug users. Prototypic item cutoffs provided higher levels of diagnostic and positive predictive power than did the standard base rate cutoffs.