<p>Adolescent substance use is a major public health concern worldwide, contributing to developmental, psychological, and social difficulties that often persist into adulthood. This meta-analysis synthesized 41 effect sizes from 13 randomized controlled trials involving adolescents with substance use problems to evaluate the effects of Cognitive-Behavioral Therapy (CBT) on psychological outcomes (depression, coping, substance use motivation) and behavioral outcomes (sexual risk-taking). Overall, CBT demonstrated significant beneficial effects across outcomes, with differential effectiveness observed depending on age, measurement, and substance use patterns. For depression, larger effect sizes were found among participants aged 18 or older, whereas effects did not differ significantly by substance use type. For coping outcomes, stronger effects were observed when assessed using the Situational Confidence Questionnaire (SCQ), while effect sizes did not differ significantly across substance use type and age groups. With respect to sexual risk-taking behaviors, CBT showed significantly greater effects among polysubstance users and participants aged 18 or older. In contrast, effects on substance use motivation did not differ significantly across both substance use type and age subgroups. These findings suggest that while CBT is broadly effective for adolescents with substance use problems, its impact may vary by developmental stage, outcome domain, and assessment approach. The results highlight the importance of considering age-related transitions and substance use complexity when tailoring CBT interventions for adolescent and emerging adult populations.</p>