Abstract
Two hypotheses were derived linking locus of control to voluntary, “completion of treatment” detoxification from methadone maintenance : (1) methadone maintenance patients with an internal locus of control will be more likely to indicate a willingness to begin detoxification, and (2) among patients indicating a willingness to begin, those with an internal locus of control would be more likely to actually begin. Subjects were 115 male methadone patients. A nonsignificant trend was found in support of the first hypothesis, while the second was reversed at a statistically significant level (r = -.30, p <. 012). The results are analyzed in terms of patient ambivalence concerning the possible outcomes of detoxification, and the need to include behavioral measures in research on personality variables and drug dependence.