Long-Term Effects of School-Based CBT in Low-Risk Children and Adolescents: A Bayesian Meta-Analysis

Depression and anxiety are increasingly common among children and adolescents. While school-based cognitive behavioral therapy (CBT) is a promising intervention, most research has focused on its effects in high-risk or symptomatic populations. This leaves a critical gap in our understanding of its effectiveness as a universal prevention strategy for the general, low-risk student population. Establishing whether CBT can benefit low-risk students is crucial for developing proactive, school-wide mental health systems aimed at preventing future problems before they emerge. This study aimed to fill this gap by evaluating the short- and long-term effects of universal school-based CBT on low-risk children and young people, providing insights for optimizing intervention programs.

Systematic searches of MEDLINE, Embase, the Cochrane Library, Web of Science, and PsyInfo were conducted from inception to January 15, 2025 to identify randomized controlled trials (RCTs) of school-based CBT for depression and anxiety in low-risk populations. Paired and regression meta-analyses of these results were conducted using Bayesian hierarchical models.

The 31 RCTs included a total of 19,865 children and young people. Compared to the control group, school-based CBT produced a statistically significant but very small improvement in depressive symptoms (SMD: -0.06, 95% CrI: -0.08 to -0.04) and a small reduction in anxiety symptoms (SMD: -0.19, 95% CrI: -0.22 to -0.17). These effects appeared to be maintained for up to 1 year. Exploratory analyses suggested that males may benefit more from anxiety interventions.

This study provides the first meta-analytic evidence that universal school-based CBT can produce small but durable, long-term preventive effects in low-risk youth. Although the very low quality of the underlying evidence means the findings are not robust enough to support widespread implementation at this time, they establish a crucial signal of effectiveness. The primary implication is that universal CBT is a promising strategy that warrants significant investment in future high-quality, large-scale trials to confirm its real-world value.