Male methamphetamine-user inmates in prison treatment: during-treatment outcomes.

Psychosocial functioning and criminal thinking of methamphetamine-using inmates were examined before and after their completion of primary treatment in three in-prison drug treatment programs (one "outpatient" and two different modified therapeutic communities [TCs]). The sample consisted of 2,026 adult male inmates in 30 programs in Indiana. Data included background, psychosocial functioning, criminal thinking, and therapeutic engagement indicators. Multilevel repeated measures analysis was used to evaluate changes during treatment, and multilevel covariate analysis adjusted for sample differences in tests of between-treatment differences. Significant improvements were found for all three treatments, but the two modified TCs showed significantly better progress than did outpatient treatment housed among the general prison population. Significant predictors of treatment progress included baseline psychosocial functioning and background, wherein higher psychosocial functioning and lower criminal thinking orientation predicted stronger therapeutic engagement. However, treatment engagement level was found to mediate during-treatment improvement and initial criminal thinking.