Several groups of drug-abusing young adults [human] who were residents of a drug-free therapeutic community were studied. Instruments [3] were used: staff ratings, sociometric ratings by members of the community and MMPI [Minnesota Multiphasic Personality Inventory] scores. All 3 measures showed objective evidence of decreasing psychopathology correlated with length of time in treatment, demonstrating the effectiveness of the therapeutic community in the rehabilitation of drug abusers. Individuals who left before completing treatment had MMPI scores indicating inability to develop social relationships; this elucidates a probable cause of the dropout phenomenon.