Subgroups among opiate addicts: a typological investigation.

To delineate homogenous subgroups among hospitalized opiate addicts, a multivariate correlational clustering technique was applied to the Minnesota Multiphasic Personality Inventory profiles of 1,500 addicts, subdivided into 10 subsamples (5 for each sex) representing four different categories of admission into treatment (civilly committed, volunteers, probationers, prisoners). Within each subsample, two homogeneous and replicable profile types were isolated. Type I (33% of all addicts) showed elevations on Scales 2, 4, and 8, suggesting marked subjective distress, nonconformity, and disturbed thinking. The much smaller Type II (about 7% of addicts) showed a single peak on Scale 4. Sixty percent of addicts thus were unclustered. The two basic types, however, were very effectively discriminated on a variety of other psychometric indexes and were consistent with the two major profile types found among alcoholics in prior research.