Anxiety and depressive disorders in children are common. The investigators in the American Great Smoky Mountains Study found that, during a 3-month period, 2.4% of children ages 9 to 16 years fulfilled the diagnostic criteria for an anxiety disorder and 2.2% met the criteria for a depressive disorder . Similar rates were found in the British Mental Health Survey, in which 3.7% of 5- to 15-year-olds had a current anxiety disorder and 1% had a depressive disorder . Comorbidity of anxiety and depression is common [3, 4], with cumulative rates suggesting that, by 16 to 17 years of age, 15% to 18% of children will have experienced an impairing emotional disorder of anxiety or depression [1, 4].
Longitudinal studies highlight that child mental health disorders persist into adulthood. In the Dunedin birth cohort study, approximately 52% to 55% of young adults with depression or anxiety met the diagnostic criteria for a mental health disorder before 15 years of age, with 75% receiving a first diagnosis before the age of 18 . Childhood anxiety increases the risk of anxiety, depression, substance misuse and educational underachievement in early adulthood . Similarly, childhood depression increases the risk of suicide, subsequent depression and substance misuse. The associated health-related burden and economic and societal costs are considerable, and the need to improve the mental health of children is being increasingly recognised as a priority at the global level [7–9].
Whilst effective psychological treatments are available, few children with emotional disorders receive them. Surveys undertaken in the United Kingdom and the United States have revealed that approximately one-third of children with anxiety disorders and less than one-half with depressive disorders had sought or received help from specialists over a 1- to 3-year period [10, 11]. The persistence of emotional disorders, as well as the immediate and future burden, and the limited reach of treatment services have led to interest in alternative approaches to improve the mental health of children.
School-based mental illness prevention programmes offer an attractive alternative to traditional treatment approaches. Systematic reviews have highlighted that anxiety and depression prevention programmes can be effective, although the results have been widely variable [12–15]. Methodologically, many of these studies are poorly designed, sample sizes are small, comparisons with other active interventions are lacking and follow-up is limited. Implementation studies whereby efficacious interventions are evaluated in suitably powered trials under everyday conditions are comparatively few and have delivered disappointing results. Recent evaluations of large, well-designed depression prevention programmes delivered for children in schools, for example, have failed to find intervention effects [16–18]. Although the results of anxiety prevention programmes have tended to be more encouraging, recent implementation trials have failed to find positive effects [19, 20]. Two important issues that will influence programme effectiveness in preventing mental health problems in children are the ways in which the programme is provided (universally versus targeted) and who delivers the intervention (health care professionals versus teachers) [12, 14, 15].
Prevention programmes can be provided universally (that is, to all of an identified population, regardless of risk status) or targeted toward those at risk of developing mental health disorders or showing early signs of a disorder . Universal programmes avoid the need for costly screening, fit better within complex school timetables, are less stigmatising and provide opportunities for primary prevention. This last point is important because many trials of prevention programmes have focused on demonstrating evidence of treatment effects (that is, reducing current symptom levels) rather than on preventive effects, such as a reduction in the emergence of new cases . Universal interventions tend to have a smaller effect than targeted programmes, however, and, in times of economic pressure, may not be considered the best use of limited resources [23, 24].
In terms of delivery, health care professionals or graduates tend to be more effective than trained school staff in delivering depression prevention programmes . Reviewers have found no difference in effectiveness between health care professionals and school staff in the delivery of anxiety prevention programmes . Direct comparisons within prevention trials between health care professionals and school staff have seldom been undertaken, however, so the most effective form of prevention programme delivery is not known.
Of the emotional health prevention programmes that have been developed, FRIENDS for Life has been identified as one of the more efficacious programmes [13, 25]. FRIENDS is based on cognitive-behavioural therapy and develops children’s skills to enhance emotional regulation, coping mechanisms and thinking styles. A pragmatic randomised controlled trial is currently underway in the United Kingdom to compare the effectiveness of universally delivered health care–led FRIENDS, school-led FRIENDS and usual school provision of personal, social and health education (PSHE) at 12 months after initiation . The purpose of the Preventing Anxiety in Children through Education in Schools (PACES) trial is to assess the medium-term (24 months) effects. First, differences in emotional health between health care– and school-led FRIENDS and usual school provision of PSHE at 24 months will be investigated. Second, the effects of the three conditions at 24 months on children with high and low levels of anxiety at baseline will be explored.