Universal prevention of anxiety and depression in school children

Anxiety and depression are common in children and adolescents, and involve individual suffering, risk of future psychiatric problems, and high costs to society. However, only a limited number of children experiencing debilitating anxiety and depression are identified and receive professional help. One approach that could possibly reduce the prevalence of these conditions is universal school-based prevention aimed at reducing the impact of risk factors and strengthening protective factors involved in the development of anxiety and depression. The current thesis aimed to contribute to the literature on universal prevention of anxiety and depression in children. Study I involved a meta-analysis of earlier randomized, and cluster-randomized trials of universal prevention of anxiety and depression. Overall, the meta-analysis showed small but significant effects of universal preventive interventions, meaning that lower levels of anxiety and depression were evident after intervention completion and partially evident at follow-up assessments. No variables were found to significantly enhance the effects, however, there was a tendency for larger effects to be associated with mental health professionals delivering the interventions. In Study II, a widely adopted prevention program called Friends for Life was evaluated in a large school-based cluster-randomized effectiveness trial. The results showed no evidence of an intervention effect for the whole sample. However, children with elevated depressive symptoms at baseline and children with teachers who highly participated in supervision, seemed to benefit from the intervention in the short term. Study III involved a 3-year follow-up of Study II and an examination of the effects of sample attrition. The results showed no long-term effects for the whole sample and no maintenance of the short-term subgroup effects observed in Study II. Finally, to increase our understanding of the development of anxiety in children and to assist future improvements of universal prevention, Study IV evaluated different trajectories of overall anxiety together with related patterns of disorder-specific symptoms in a school-based sample over 39 months. Evidence favored a model of three different developmental trajectories across age. One trajectory was characterized by increasing levels of overall anxiety, but fluctuating disorder-specific symptoms arguably related to the normal challenges of children’s developmental level, which warrants an increased focus on age-relevant challenges in universal prevention. The four studies provide further understanding of the overall effectiveness of universal prevention of anxiety and depression in children, the short- and long-term effects of universal prevention in a Swedish context, and ideas for further development of preventive interventions.