The results of interventions to enhance patient adherence to medication have been inconsistent. This research investigated the utility of an enhanced adherence training programme to ascertain its effectiveness and the possible mechanisms of that effect. Forty-six clinicians were trained in 'medication alliance', and data were collected from 51 patients matched to the clinician. Data on clinician changes in skills, knowledge, and attitudes, in relation to enhancing patient adherence and patient changes in adherence, insight, and psychopathology were collected at baseline and at 6 and 12months. The quality of the therapeutic relationship between the clinician and the patient was also assessed. The results indicated significant improvements in both clinician and patient measures, the majority of which were maintained over time. The quality of the therapeutic relationship was also enhanced. A hypothesized explanatory model accounting for the data was supported. It was concluded that clinician training to support improved patient adherence should include strategies that also enhance the therapeutic alliance.