Gambling is now widely acknowledged to be a major public health (PH) issue. The Office for Health Improvement and Disparities conservatively estimated that gambling harm is associated with an annual cost of £1.05–£1.77 billion in England alone. Marionneau et al have categorised gambling harms into seven themes: (1) financial, (2) relationship/conflict, (3) emotional and psychological (mental health), (4) health decrements (physical health), (5) employment/education, (6) cultural and (7) criminal activity. In this understanding, gambling harms are not restricted to individual experiences: they also impact families, the wider community and society, and hence they require a whole systems, PH approach, anchored in population-level interventions to reduce harms. We aim to identify the effects of interventional PH laws and regulations on the harms associated with gambling.

We limit our focus to interventional PH laws and regulations within a comprehensive search of scientific and legal databases, grey literature and books. Following Population, Intervention, Comparator, Outcome, Study, Timing inclusion criteria, evidence will be screened and appraised in Covidence by two reviewers (MF and TP). Included evidence will be analysed and synthesised using a narrative synthesis approach. Methodological quality will be appraised using the relevant risk of bias tool. Randomised controlled trials will be assessed using the Cochrane risk of bias tool (RoB2), Risk Of Bias In Non-randomised Studies - of Interventions (ROBINS-I) will be used for other non-randomised studies. Qualitative studies will be appraised using the EPPI reviewer software for systematic reviewing.

The review protocol is registered with PROSPERO (International prospective register of systematic reviews) at the National Institute for Health Research and the Centre for Reviews and Dissemination (CRD) at the University of York (CRD42024574502). We aim to define a theory of change and produce a context-mechanism-outcome framework with relevant experts using the findings. We plan to disseminate the findings through peer-reviewed publications, meetings with relevant experts and international conference presentations.

Adolescence is a time of rapid physical, social and psychological development and many risk factors for mental disorders have their roots in this age period. Primary prevention through school platforms has been extensively used and evaluated, but many interventions have poor uptake, high dropout and limited long-term sustainability. Mental health is a complex phenomenon and may be best supported through multicomponent interventions that more holistically consider inner, social and environmental levels. Character education-focused interventions are effective for improving adolescent psychosocial functioning and mental well-being. Therefore, an intervention that focuses on developing these strengths and is delivered within a school environment, through an adolescent-informed approach using creativity-focused components, has the potential to improve adolescent mental health and well-being.

This protocol describes the YiPEE cluster-randomised controlled trial with concurrent mixed-methods process evaluation and economic evaluation, which aims to determine the impact of a multilevel multicomponent intervention in schools in Chennai, Tamil Nadu, India. Clusters—defined as schools which include Grades 6–8 (ages 11–16 years), will be randomised to intervention (n=15) or control (n=15). The intervention consists of: an 8-week classroom-based component, a 12-week teacher-focused component and a board comprising members from across the whole school. All children attending Grade 7 (aged 12–15) will be exposed to the classroom component, and teachers who actively teach Grade 7 will be invited to participate in the teacher component. Within schools, students for the individual-level evaluation will be included if they are: (1) aged 12–15 years; (2) currently attending Grade 7; (3) competent to give consent and (4) have a legal guardian competent of giving consent. We aim to sample a minimum of 100 students from each school (n=3000). All teachers of Grades 6–8 will be recruited for the evaluation. The primary outcome is symptoms of anxiety and depression measured using an abbreviated version of the UNICEF MMAPP tool. The primary analysis will be intention-to-treat, comparing the mean change in mental health score between baseline and endline, between intervention and control clusters. In addition, we will record school monitoring data (student attendance, student grades). Individual interviews with students and teachers, focus group discussions with school staff, and ethnographic observations will provide data for the process evaluation. For the economic evaluation, the combined direct and non-direct costs will be compared with changes in mental health in the intervention arm.

The trial is approved by the Ethics Council of the Schizophrenia Research Foundation, India, with approval number EC/NEW/INST/2023/TN/0329. We plan to publish the main impact, process and economic evaluation results as academic publications in international peer-reviewed journals in 2026.

Clinical Trials Registry—India (CTRI/2024/07/070949).