Abstract
Mental health problems are the leading cause of childhood disability worldwide, resulting in poor outcomes for children and young people that persist into adulthood. It is essential that those young people most at risk of developing mental health problems receive effective preventative interventions. Whilst there have been a number of systematic reviews which have examined the effectiveness of secondary prevention interventions for specific groups of children and young people, or to address identified mental health concerns, no review has engaged with the breadth of this literature. We conducted a systematic review of systematic reviews to map this complex field of secondary preventative interventions and identify effective interventions to prevent mental health problems in children and adolescents aged 3-17 years. The review protocol was registered on PROSPERO. We searched five electronic databases from inception to February 2023. The certainty of the evidence was appraised using the AMSTAR 2. We included 49 unique systematic reviews each including between 2 and 249 (mean 34) unique studies; the majority of which were reviews which included only or mostly randomised controlled trials (70%). The reviews examined selective interventions (defined as interventions which are delivered to sub-group populations of young people at increased risk of mental health problems) (n = 22), indicated interventions (defined as interventions which target young people who are found to have pre-clinical symptoms) (n = 15) or a synthesis of both (n = 12). The certainty of the evidence in the reviews was rated as high, (n = 12) moderate (n = 5), low (n = 9) and critically low (n = 23). We found evidence to support both selective and indicated interventions in a range of populations and settings, with most of this evidence available for children and young people in their mid-years (6-10 years) and early adolescence (11-13 years). There was a large body of evidence suggesting that resilience enhancing, cognitive behaviour therapy-based and psychoeducational interventions for children who experience adversity, or those with subclinical externalising problems may offer promise. Early selective interventions for a subpopulation of children and young people who have experienced adversity which combines risk reduction and resilience enhancing approaches directed at children and their families may be effective at reducing mental health problems.