Ten Years Later: What Have We Learned from Implementing the WHO Designed Problem Management Plus Globally? A Scoping Review of Barriers and Lessons Learned

Problem Management Plus (PM+) is a brief transdiagnostic intervention developed by the World Health Organization in 2015 and is intended to be delivered by lay counselors to address the vast mental health treatment gap particularly in low- and middle income countries. Over the last 10 years, PM+ has been implemented across the globe with numerous randomized control trials providing evidence for its efficacy. This scoping review examines the global implementation of PM+, identifying barriers, lessons learned, and key practices for successful deployment across diverse settings. Following PRISMA guidelines, a comprehensive search across five electronic databases (Academic Search Complete, PsycINFO, MEDLINE, CINAHL, and SocINDEX) was conducted. Two pairs of authors independently reviewed and selected peer-reviewed articles, with all four reviewers extracting data. Of the 292 studies retrieved, 82 articles met the eligibility criteria and were included in the review. The literature comprised 19 randomized controlled trials, 18 descriptive studies, 14 study protocols, 12 mixed methods studies, eight field reports/reflections, six feasibility/pilot studies, and five qualitative studies. Thirty-one articles addressed implementation barriers, while 30 discussed lessons learned. Using an ecological systems framework, we categorized findings into three levels: individual/ micro (participant and counselor engagement), community/mezzo (training and implementation), and institutional/macro (scaling up PM+ within governmental and political structures). Published research demonstrates the effectiveness of the PM+ intervention in mediating symptoms of common mental health distress. This review synthesizes key implementation barriers and effective strategies for scaling PM+ across settings that can be used by researchers and service providers in future implementation.