A national case-comparison trial was conducted with community mental health staff who received training and mentoring in the Reasons For Use Package compared to a matched sample. A mixed methods approach included surveys, focus groups and a case study. The intervention group reported improvement in perceived knowledge and confidence. Staff benefitted from a package providing a framework for implementing strategies with service users. Consumer respondents also gave positive feedback on their experience of using the RFUP. The RFUP shows promise as an aid to dual diagnosis capacity building and has a positive impact for consumers.