Objective: This study aimed to evaluate the effectiveness of BEHAVIORAL Activation Therapy (BAT) on reducing anhedonia and enhancing school PARTICIPATION among adolescents in Malaysia. Methods and Materials: A randomized controlled trial design with a five-month follow-up was used, involving 30 adolescents randomly assigned into intervention and control groups (n = 15 each). The intervention group received 12 weekly sessions of BEHAVIORAL Activation Therapy, each lasting 45–60 minutes, targeting increased PARTICIPATION in rewarding and meaningful activities. The control group received no intervention during the study period. Anhedonia was measured using the Snaith–Hamilton Pleasure Scale (SHAPS,Snaith et al., 1995), and school PARTICIPATION was assessed by the School Function Assessment (SFA,Coster et al., 1998) at pre-test, post-test, and five-month follow-up. Repeated measures ANOVA with Bonferroni post-hoc tests were performed using SPSS-27. Findings: Repeated measures ANOVA demonstrated significant improvements in the intervention group on both anhedonia (F(2, 56) = 61. 54, p <. 001, η² =. 70) and school PARTICIPATION (F(2, 56) = 36. 42, p <. 001, η² =. 56). Mean anhedonia scores in the intervention group significantly decreased from pre-test (M = 10. 47, SD = 1. 36) to post-test (M = 5. 13, SD = 1. 21) and remained stable at follow-up (M = 5. 20, SD = 1. 33). Similarly, school PARTICIPATION significantly increased from pre-test (M = 56. 27, SD = 6. 84)to post-test (M = 72. 40, SD = 5. 92), with effects sustained at follow-up (M = 71. 53, SD = 6. 15). Post-hoc comparisons confirmed that all significant changes occurred between pre-test and post-test, with stability from post-test to follow-up. Conclusion: Thes findings suggest the therapy suitability as an effective therapeutic approach within educational and psychological practice settings.