Can a motivational-interviewing-based outpatient substance abuse treatment achieve success? A theory-based evaluation

This study evaluated a South African outpatient drug counselling centre’s motivational interviewing-based treatment programme from theory and outcomes-based perspectives. 142 participants were interviewed at admission to the programme and followed up 6 and 10 weeks later. Trajectories of substance use, substance dependence, self-efficacy, motivation (using SOCRATES sub-scales of Problem Recognition, Ambivalence and Taking Steps) and NA/AA affiliation were examined. Self-efficacy and SOCRATES Taking Steps scores increased and were significantly associated with substance use levels, which decreased significantly over time. Higher self–efficacy scores at end-of-treatment (6 weeks) predicted lower substance use scores at 10 weeks. More programme attendance was associated with lower levels of substance use/dependence. Abstinence was achieved by 47% of participants.Keywords: substance abuse, substance dependence, treatment outcomes, self-efficacy, motivation, evaluation