Background: Childhood anxiety and depression lead to great distress and impairment. Preventing them simultaneously in early life is critically important. We evaluated the long-term efficacy of an emotion regulation-based (ER) and a behavioural activation-based (BA) program. Both aimed to build resilience to prevent worry, a transdiagnostic feature across anxiety and depression. Methods: Participants were 316 students (52.2% female; 8–13 years) from six South Australian primary schools. Schools were randomised to the ER, BA or a control condition. Measures of resilience, worry, anxiety, and depression were taken at pre- and post- program, and at 6- and 12-month follow-up. In addition, levels of emotion regulation, behavioural activation and resilience were measured as potential mediators of changes in anxiety and depression. Results: No significant condition × time interactions were observed. However, the percentage of children who met the clinical cut-offs for generalised anxiety disorder and major depressive disorder decreased significantly in the BA condition at 12-month follow-up, as well as the percentage of children who met the clinical cut-off for obsessive compulsive disorder in the ER condition. Furthermore, emotion regulation mediated the relationship between condition and worry at post-program in the ER condition. Limitations: The sample size is relatively small. Reliance on child self-report may have resulted in inaccurate responses. Conclusion: The ER and BA transdiagnostic prevention programs for childhood anxiety and depression showed promising results for certain anxiety disorders not otherwise observed in universal school-based studies. Future research should consider evaluating the programs with a larger sample using alternative outcome measures.
- Universal prevention