School-based Universal Prevention for Anxiety and Depression in Sweden: A Cluster-randomized Trial Using the FRIENDS for Life Manual

Mental illness is a major health problem in children and young people, and there is evidence that mental illness is increasing among young people in the population. More than 80 % of the cost to society of mental illness in children in Sweden is the cost of treatment and care. Only a small portion thus consists of preventive interventions. The report "Programs to prevent mental illness in children - a systematic literature review" (2010) from the Swedish National Council on Technology Assessment (SBU), concluded that no prevention program has evidence of efficacy under Swedish conditions. A target for future prevention work is according to the authors SBU-report that programs that are used have scientific support and evaluated in Sweden. Based on the review the report's authors recommend that five programs should be prioritized for further evaluation. One of these five programs is FRIENDS for life, a prevention program to prevent anxiety.

Anxiety and depression are the most common psychiatric problems in children and adolescents. Untreated anxiety disorders often have a chronic course or may occur again and depression in adolescents often continue into adulthood anxiety and depression in children and adolescents predicts a variety of psychiatric diagnoses later in life, leading to difficulties with school and friends, and lead to increased risk of suicidal acts, alcohol and drug abuse.

In comparison with the treatment of mental disorders, there is relatively limited knowledge about prevention. There are at least two very important reasons to investigate further preventive interventions for anxiety and depression. (1) Only about 20% of children and adolescents with anxiety or depression use health services. (2) Some children stop treatment and almost 40% do still fulfill criteria for the disorder after treatment.

FRIENDS for life is one of the most evaluated prevention programs internationally. The program has shown promising results in research. In Sweden there are no high-quality evaluation of prevention programs targeting anxiety and depression. Based on the high incidence of anxiety and depression and its serious consequences it is of utmost importance to investigate whether prevention programs work in a Swedish context. The overall aim of the present study is to evaluate FRIENDS for Life in Sweden. The following research questions guide the study:

1. Do FRIEND for life affect children's estimates of anxiety and depression symptoms and parents' estimates of children's anxiety symptoms, on the scales Spence Children's Anxiety Scale? Is the possible impact still visible after 12 months?
2. Do FRIEND for life affect the presence of anxiety diagnoses and subclinical anxiety at 12 months according to ADIS-C/P interview?