Client initiative, inertia, and demographics: more powerful than treatment interventions in methadone maintenance?

A major treatment intervention, previously reported in the literature, was conducted in which methadone clients were able to regulate their maintenance dose on a weekly basis. In this paper, the relationships among the intervention outcomes, demographic and personality variables, and treatment assignment are presented. The analyses indicate that personality, demographic, drug career, and treatment history variables did not interact with treatment assignment to produce particular outcomes. Nevertheless, outcome could be predicted by baseline illicit opiate use, prestudy methadone dosage, an interaction of age and ethnicity, and variables related to clients' initiative versus inertia with regard to treatment.