Have digital self-help mental health intervention research studies reached and been adopted by Global Majority young people? A Mapping Review (Preprint)

BACKGROUND Young people in Global South countries, and racially and ethnically minoritised young people in Western countries, are underserved by current clinic-based mental health provision. Self-help digital mental health interventions (DMHIs) offer a scalable approach to address the global needs-access gap for young people’s mental health. Most extant research into self-help DMHIs is predominantly with White young people in Western high-income contexts, thus little is known about the acceptability and effectiveness for underserved Global Majority populations. OBJECTIVE The objective of this mapping review was to (1) examine whether contemporary self-help DMHI research studies have reached and been adopted by young people of the Global Majority, and to summarise available evidence on their acceptability and effectiveness for these populations; and (2) to assess whether self-help DMHIs studies report participant’s race and in line with research reporting standards. METHODS A mapping review, registered on the OSF (https://osf.io/ebz3v/files/4k5zx), was conducted using a search of PubMed and APA PsycNet databases with supplementary screening of Google Scholar and the Cochrane Database (from August – December 2024). Peer reviewed intervention studies published from 2019 onwards were eligible if they evaluated self-help DMHIs targeting anxiety, depression, emotional problems or wellbeing among young people aged 10-24 years. Data on study characteristics, sample demographics and implementation features were extracted in line with the RE-AIM (Reach, Effectiveness, Adoption, Implementation, Maintenance) framework. Findings were synthesised the using RE-AIM framework, with extraction and analysis focussed specifically on Global Majority particiapnts. Results were summarised using narrative synthesis and tabular mapping. RESULTS In total, we identified and screened 1882 papers, of which 105 full texts were considered relevant and assessed for eligibility. 37 papers were eligible, including 30,075 participants in total. Only 9.2% of participants were clearly identified as belonging to the Global Majority by ethnicity and just 10.9% of studies were conducted in LMICs. Reporting of race and ethnicity was highly inconsistent; 40% of studies did not report ethnicity and 62% did not report race. Aggregated or binary categories (e.g. “non- White”) were common. Only one study disaggregated effectiveness outcomes by ethnicity, and fewer studies examined differential attrition or engagement. Cultural adaptation or co-design was described in 16% of studies primarily in low-and-middle-income or indigenous contexts. Maintenance outcome beyond six months were rarely reported. CONCLUSIONS Despite their promise as scalable interventions, self-help DMHIs have not yet equitably reached young people of the Global Majority, who remain underrepresented and marginalised within the evidence-base. Inconsistent reporting of race and ethnicity, limited cultural adaptation, and a lack of disaggregated effectiveness and maintenance data constrain claims of scalability and equity. Future research must adopt equity centred design, transparent demographic reporting particularly co-design, and long-term implementation evaluation to ensure digital mental health interventions meaningfully serve diverse global populations.