Fostering resilience in conflict-affected schools: A randomized controlled trial of the 3C program's effects on...

Afro-Colombian adolescents in Tumaco face high mental-health risks due to armed conflict and structural marginalization. We tested the short-term efficacy of the 3C program to strengthen resilience, compassion, and prosocial behavior and to reduce anxiety, depression, and PTSD. Mixed-methods cluster RCT with concurrent triangulation; multilevel mixed-effects models with multiple imputation; assessments at baseline, 6, and 9 months. Resilience increased by 13.14 points at 6 months (large effect, d = 0.89) and remained elevated at 9 months. Anxiety and PTSD screenings were lower in the intervention group across follow-ups. Compassion and prosocial behavior improved at 6 months but attenuated by 9 months. Depression screenings decreased at 6 months and rebounded at 9 months. Qualitative data aligned with these patterns (students reported sustained use of stress-management skills and peer support). 3C demonstrated short-term efficacy for resilience, anxiety, and PTSD but showed limited durability for compassion, prosociality, and depression without ongoing reinforcement. The pattern of effect attenuation-particularly the complete depression rebound-indicates that 3C provides a foundational component requiring integration with booster sessions to sustain socioemotional gains.