Psychological treatment that reduces anxiety has been found to be beneficial to benzodiazepine withdrawal. High drop-out and relapse rates, however, have also been reported. They might be due to a heightened anxiety level maintaining the drug-taking habit or to the addictive potency of the drug, which is not addressed by the intervention strategies. In the present study, initial assessment data were compared among treatment refusers, drop-outs and completers – successful as well as unsuccessful ones – of a psychological treatment programme in support of benzodiazepine withdrawal. Treatment refusers showed a more negative current mood state than those consenting to treatment. Internal locus of control was predictive of premature termination and unsuccessful completion of the treatment trial. Neither medication-related variables nor anxiety or depression were found to influence the success of treatment. Perceived control over medication intake is thought to reduce compliance with the treatment regimen – a pattern that may be consistent with the addiction hypothesis.