The Effectiveness of a Motivational Interviewing Treatment for Help-Seeking Problem Gamblers in a Community Organization.

Motivational Interviewing (MI) has been used as an approach to enhance readiness for change and behavior modification in a range of addiction and substance use disorders. Large meta-analyses comparing MI with non-MI interventions point to mixed conclusions about the short-term and long-term effectiveness of MI, with participant, outcome, and delivery factors being important moderators. The current study aimed to assess the immediate (1-2 weeks) and long-term (18 months) effectiveness of MI when delivered at the first point of client contact at a community gambling help counselling service and to investigate whether practitioners' MI adherent and non-adherent behaviors were significant predictors of change in client outcomes. There were 146 individuals presenting for gambling help counselling at an Australian not-for-profit organization who participated in this research. From the overall sample, 55% completed the 18 months follow-up assessment. Multilevel modelling showed a significant reduction in participants' problem gambling severity and psychological distress, which was a small effect size change in the short-term and large effect size change by the 18 months follow-up. While MI adherent practitioner behaviors were not found to be significant predictors of improvement in participants' problem gambling severity and psychological distress, MI non-adherent practitioner behaviors were significant predictors of deterioration in participants' problem gambling severity and psychological distress. This study highlights the importance of excluding MI non-adherent (confront and persuade) practitioner behaviors in order to prevent deterioration in client outcomes.