The Commission argues that despite the availability of effective mental health interventions, most people who could benefit from them do not receive them, creating a substantial implementation gap. The authors propose five key transformations: integrating research and implementation from the outset, embedding equity into intervention development and dissemination, applying a complexity science perspective, expanding beyond traditional randomised controlled trials, and adopting transdisciplinary approaches to knowledge generation. They emphasise the importance of conducting research within real-world systems and communities to produce evidence that is actionable, scalable, and responsive to local contexts. Overall, the Commission provides a comprehensive roadmap for reshaping implementation research to improve access to effective mental health care worldwide.