This study is a single-arm feasibility trial designed to evaluate the implementation, acceptability, and preliminary effects of a culturally adapted Compassionate Mindful Resilience (CMR) intervention among adolescents in Thailand. The study is conducted in a secondary school setting and targets students aged 16 to 18 years.

Adolescence is a critical developmental period associated with increased emotional vulnerability, academic pressure, and exposure to mental health risks. In Thailand, recent evidence indicates rising levels of stress, anxiety, and reduced psychological well-being among young people. School-based preventive interventions that strengthen internal coping skills are therefore a public health priority. While mindfulness-based interventions have demonstrated benefits in Western contexts, there is limited evidence regarding compassion-focused mindfulness programs that are culturally adapted for Thai adolescents.

The CMR intervention is a structured, manualized behavioral program that integrates mindfulness, self-compassion, and resilience-building skills. The program was originally developed by MindfulnessUK and subsequently adapted for the Thai adolescent context through a co-production process involving students, teachers, and school counselors. Cultural adaptations focused on language use, contextual relevance of examples, and alignment with the Thai educational environment, while maintaining fidelity to the core theoretical framework.

All participants enrolled in the study will receive the CMR intervention. The program consists of four weekly group sessions, each lasting approximately 90 minutes, delivered after school hours to minimize disruption to academic activities. Sessions include guided mindfulness practices, group discussions, and practical exercises aimed at increasing present-moment awareness, cultivating self-compassion, improving emotional regulation, and strengthening resilience. Home practice activities are encouraged between sessions to support skill integration into daily life.

The primary objective of the study is to assess feasibility. Feasibility outcomes include recruitment rate, retention rate, session attendance, intervention fidelity, and participant acceptability. These indicators will inform whether the intervention can be delivered as planned in a Thai school setting and whether progression to a larger-scale trial is justified.

Secondary objectives explore preliminary changes in mental health-related outcomes. These include mindfulness, self-compassion, resilience, and overall well-being, measured using validated Thai-language instruments before and after completion of the intervention. Although the study is not powered to test effectiveness, these data will provide estimates of variability and potential effect sizes to inform the design of a future randomized controlled trial.

Participant safety is addressed through a predefined distress protocol. A school counselor is available during all intervention sessions to provide immediate support if participants experience emotional distress. Ethical approval has been obtained from the relevant institutional ethics committee, and written assent from participants, along with parental or guardian consent, is required prior to enrollment.

Overall, this feasibility study will generate critical information on the practicality, acceptability, and preliminary impact of the Compassionate Mindful Resilience program for adolescents in Thailand. The findings will guide the development of a future definitive trial and contribute to the evidence base for culturally appropriate, school-based mental health promotion interventions in low- and middle-income settings.

Detailed Description Study Framework and Theoretical Basis This feasibility study constitutes Phase 3 of a comprehensive research project designed to address the rising rates of stress, anxiety, and substance use risks among Thai adolescents. The intervention utilizes the Compassionate Mindful Resilience (CMR) programme, which integrates secular mindfulness with compassion-based approaches to enhance cognitive resilience and emotional regulation. While MBIs have shown efficacy in adult populations, this study evaluates a culturally adapted version specifically for the Thai secondary school context, where collectivist values and Buddhist traditions may influence implementation.

Trial Design and Procedural Workflow The study employs a single-arm, pre-post feasibility design. This approach is selected to evaluate implementation parameters and participant engagement prior to committing to a full-scale randomized controlled trial (RCT).

• Intervention Delivery: The CMR programme consists of eight modules delivered over four weekly 90-minute group sessions. Sessions are conducted after school hours (provisionally 16:00-17:30) to minimize academic disruption and mitigate potential stigma associated with mental health initiatives.
• Fidelity and Facilitation: The programme is delivered by a PhD candidate trained in CMR under academic supervision from Queen's University Belfast. Delivery fidelity is maintained through adherence checklists, session logs, and standardized recap materials for participants who miss sessions.
• Stratified Sampling: To ensure developmental diversity, the study utilizes stratified random sampling across Grades 10, 11, and 12, aimed at achieving a balanced representation from the student population.

Technical Application of Participation Models

The research process incorporates established participatory frameworks to assess the depth of stakeholder engagement:

• Hart's Ladder of Children's Participation: Evaluates whether youth involvement moves beyond tokenism to "Consulted but Informed" and "Adult-Initiated Shared Decisions"
• Arnstein's Ladder of Participation: Used to track the transition toward "Partnership" and "Delegated Power" during the co-production and evaluation phases.

Statistical Analysis Plan

The analysis focuses on determining the feasibility of the protocol for future larger-scale implementation:

• Feasibility Metrics: Recruitment rates, consent rates, session attendance, and participant retention will be analyzed using descriptive statistics.
• Preliminary Effectiveness: Quantitative changes in psychosocial outcomes will be assessed using paired t-tests or non-parametric equivalents. Effect sizes (Cohen's d) will be calculated to estimate the magnitude of change for future power calculations.
• Exposure Analysis: An exploratory subset analysis will be reported for participants who attend at least 75% of the sessions (three out of four) to investigate dose-response relationships.

Qualitative Process Evaluation To complement quantitative data, a process evaluation will explore the acceptability and contextual relevance of the programme.

• Thematic Analysis: Post-intervention focus groups and brief exit interviews will be audio-recorded, transcribed verbatim in Thai, and translated into English.
• Analytical Rigor: Qualitative data will be managed using NVivo software and analyzed via Reflexive Thematic Analysis. A second coder will review a subset of transcripts to ensure credibility and an audit trail will be maintained.

Data Security and Transfer Protocols

• Pseudonymization: All data are de-identified at the source using study codes; identifiable information remains in Thailand and is not transferred.
• Electronic Management: Scanned documents and audio transcripts are stored on encrypted, password-protected systems with role-based access.
• Cross-Border Transfer: Pseudonymized data transferred for analysis utilize encrypted channels in compliance with university governance and data protection legislation.

Inclusion Criteria:

• Adolescents between 16 and 18 years of age at the time of enrollment.
• Current students in Grades 10 to 12 (Mathayom 4-6) at a Thai Secondary School in Northeastern Thailand.
• Willingness to engage in a mindfulness-based intervention programme.
• Ability to understand and communicate in the Thai language.
• Ability to provide informed consent (dual consent from both the student and a parent/legal guardian is required).

Exclusion Criteria:

• Significant mental health conditions that may impede participation, such as schizophrenia, bipolar I disorder, or severe major depression with psychotic features.
• Cognitive impairments that prevent comprehension of the mindfulness intervention.
• Concurrent involvement in another psychological intervention that might confound the study results.

Pseudonymized individual participant data that underlie the results reported in academic publications may be made available to researchers who provide a methodologically sound proposal.

The pseudonymized study results and supporting documentation (Protocol and Informed Consent Forms) will become available upon the completion of the study and subsequent publication of results in peer-reviewed journals, anticipated in 2026. These materials will be maintained on the Queen's Research Portal for at least the duration required by university research governance and open-access policies. Participants may request the deletion of their individual data only up to 7 days after the end of all data-collection activities, after which data is de-identified and aggregated for analysis.

Aggregated findings and research outputs will be available to the general public, educators, and policymakers through open-access academic publications and the institutional repository. While raw individual participant data (IPD) will not be shared to protect the privacy of the minors involved, the Study Protocol (v3.1) and Informed Consent Forms may be accessed by researchers and stakeholders via the Queen's Research Portal. Requests for further technical information regarding the cultural adaptation process or feasibility metrics can be directed to the Research Ethics Officer or the Principal Investigator.

As this is a single-arm feasibility study, it is conducted as an open-label trial. There is no masking of participants or the investigator. Specific details regarding the open-label nature include:

• Intervention Delivery: The PhD researcher facilitates the sessions and collects all primary data, making masking of the investigator impossible.
• Participant Awareness: Students are fully informed of the Compassionate Mindful Resilience (CMR) content during the information session and through the Participant Information Sheet prior to consent.
• Absence of Control Group: Since no control group or placebo is utilized in this feasibility stage, there is no allocation concealment.
• Qualitative Analysis: The investigator also conducts the focus group discussions and exit interviews, ensuring transparency in participant interaction.
• Data Integrity: To reduce bias during analysis, quantitative data from questionnaires are pseudonymized at the source using study codes.