Effective mental health promotion, prevention, and treatment approaches exist but are not widely delivered at-scale to large groups or populations. Most people who could benefit from evidence-based mental health interventions—defined broadly to encompass policies, programmes, and individual-level practices or services—do not receive them. This implementation gap is sometimes termed a know–do gap—we know what mental health interventions can work, but we often do not know how to do those interventions in real-world settings. The growing field of implementation research, which seeks to understand what, why, and how interventions work (or do not work) in real-world settings, aims to identify approaches to overcome barriers to scaling. Although some progress has been made, implementation research can fall short of this goal. Often, research produces both interventions and implementation strategies (eg, financing, facilitation, training to improve mental health literacy or reduce stigma) that are difficult to deliver at scale owing to misalignment with the political, cultural, policy, system, community, provider, and individual realities of real-world settings. This Commission considers strategies for transforming how we conduct research to produce more actionable evidence to narrow the mental health implementation gap.
Transformations to the discovery process, including who produces evidence and how it is produced, are needed. Key principles for transformation, discussed in detail in this Commission, are the need to (1) integrate research and real-world implementation; (2) centre equity in mental health intervention and implementation research; (3) apply a complexity science lens to mental health research; (4) expand designs beyond the randomised clinical trial (RCT), including embracing rigorous non-experimental approaches; and (5) value transdisciplinarity across endeavours. The Commission takes a global health perspective, but the recommendations for transforming mental health implementation research are driven by research from high-income countries (HICs), where most mental health implementation research to date has been funded and conducted. The Commission’s recommendations incorporate research from both HICs and low-income and middle-income countries (LMICs) and call for strategies to expand mental health implementation research in LMICs.