The goal of this clinical trial is to learn if a combined intervention of summer camp and letter-writing support works to improve psychological resilience in disadvantaged adolescents in Liangshan, Sichuan. The main questions it aims to answer are:

Does the "summer camp + letter-writing" intervention improve resilience in adolescents who face poverty, lack of parental care, or social risks?

Does this intervention reduce depression and anxiety symptoms?

Researchers will compare adolescents who join the summer camp and receive monthly letters to those who do not receive this program to see if the intervention helps their mental health and coping skills.

Participants will:

Attend a 5-day summer camp that includes group games, emotion expression activities, life education, and learning support

Receive monthly letters from trained university student volunteers for about 10 months after the camp. The letters will encourage them, give advice, and help them practice what they learned in the camp

Complete surveys about their resilience, depression, and anxiety before the intervention, during it, at the end, and 6 months later

This study will also look at whether the program is cost-effective, meaning if it brings mental health benefits at a reasonable cost.

This study will test a new way to help disadvantaged adolescents build psychological resilience. Psychological resilience means having the strength to handle challenges and stress in life. Many adolescents in Liangshan, Sichuan, face poverty, lack of parental care, or social risks, which increase their chances of depression, anxiety, and social withdrawal.

Researchers designed a program with two parts:

Summer camp (first month)

Participants will attend a 5-day summer camp held at a local school. University student volunteers will lead activities such as:

Team-building games to build trust and cooperation

Emotional expression through art, music, and storytelling

Life education and future planning to raise hope and self-confidence

Learning support and academic guidance The camp will provide a safe and supportive environment where adolescents can build positive relationships and learn skills to cope with difficulties.

Letter-writing support (after the camp, for 10 months)

After the summer camp, each participant will be paired with a trained university student volunteer. The volunteer will write a letter to the participant each month. Letters will:

Encourage and support the participant emotionally

Remind them to use the skills learned during the camp

Share stories, advice, and caring words to reduce loneliness

Participants will be randomly assigned to either the intervention group, who will join the camp and receive letters, or the control group, who will continue their normal school life without this program. All participants will complete surveys before the program, halfway through, at the end, and 6 months later to measure:

Psychological resilience

Depression symptoms

Anxiety symptoms

The study will also check if this program is safe, acceptable to adolescents, and cost-effective. There are no known major risks. The program does not replace professional therapy but provides social and emotional support. If any participant shows signs of severe mental health issues, the research team will help them get professional care.

This study aims to find out if combining a short-term camp with long-term letter-writing support can sustainably improve adolescents' mental health in low-resource areas. If proven effective, it may offer a scalable and low-cost way to support disadvantaged youth in rural China.

Inclusion Criteria:

• Students enrolled in Grade 7 or Grade 8 (junior middle school) in selected schools in Yuexi County, Liangshan Prefecture, Sichuan Province.
• Identified as "children in adversity," including those from economically disadvantaged families, left-behind children, children with disabilities, or other children deemed at-risk by school officials.
• Able to understand and complete psychological questionnaires.
• Mentally and physically able to participate in group activities and engage in written communication.
• Willing to participate in the study and provide informed assent.
• Legal guardian has signed written informed consent for participation.

Exclusion Criteria:

• Children with serious psychiatric or developmental disorders (e.g., autism spectrum disorder, intellectual disability) that impair comprehension or participation.
• Currently receiving professional psychological counseling or treatment that may interfere with the study protocol.
• Participation in other mental health interventions in the past year.
• Planning to transfer, drop out, or leave the region during the study period.
• Judged by the research team to be unsuitable for participation due to medical or other reasons (e.g., serious physical illness that prevents participation in camp activities).

This study involves vulnerable child participants, and individual-level data will not be shared due to ethical and privacy concerns. Only aggregate-level results will be made available in publications or upon request.