ABSTRACT: BACKGROUND:Mental health policy can be an essential and powerful tool to improve a population's mental health. However, around one third of countries do not possess a mental health policy, and there are large disparities in population coverage rates between high- and low-income countries. The goal of this study is to identify the transition and implementation challenges of mental health policies in both high-income countries (HICs) as well as middle- and low-income countries (MLICs). METHODS:PubMed, Cochrane Library and Campbell Library were searched from inception to 31 December 2017, for studies on implemented mental health policies at the national level. Abstracts and the main texts of papers were double screened, and extracted data were analysed through thematic synthesis. RESULTS:A total of 93 papers were included in this study, covering 24 HICs, 28 MLICs and 5 regions. Studies on mental health policies, especially those of MLICs, kept increasing, but MLICs were still underrepresented in terms of publication quantity and study frequency. Based on the included studies, nine policy domains were summarized: service organizing, service provision, service quality, human resources, legislation and human rights, advocacy, administration, surveillance and research, and financing and budgeting. HICs incrementally enriched their policy content in all domains over centuries of development; following HICs' experience, mental health policies in MLICs have boomed since the 1990s and quickly extended to all domains. Implementation problems in HICs were mainly related to service organizing and service provision; for MLICs, more severe implementation problems converged on financing and budgeting, administration and human resources. CONCLUSIONS:Mental health policy developments in both HICs and MLICs present a process of diversification and enrichment. In terms of implementation, MLICs are faced with more and greater challenges than HICs, especially in funding, human resources and administration. Therefore, future efforts should not only be made on helping MLICs developing mental health policies, but also on promoting policy implementation under MLICs' local context.
