School-based interventions to prevent anxiety and depression in children and young people: a systematic review and network meta-analysis

Abstract

Background: Rates of anxiety and depression are increasing among children and young people. Recent policies have focused on primary prevention of mental disorders in children and young people, with schools at the forefront of implementation. There is limited information for the comparative effectiveness of the multiple interventions available.

Methods: We did a systematic review and network meta-analysis, searching MEDLINE, Embase, PsycINFO, and Cochrane Central Register of Controlled trials for published and unpublished, passive and active-controlled randomised and quasi-randomised trials. We included educational setting-based, universal, or targeted interventions in which the primary aim was the prevention of anxiety and depression in children and young people aged 4-18 years. Primary outcomes were post-intervention self-report anxiety and depression, wellbeing, suicidal ideation, or self-harm. We assessed risk of bias following the Cochrane Handbook for Systematic Reviews of Interventions. We estimated standardised mean differences (SMD) using random effects network meta-analysis in a Bayesian framework. The study is registered with PROPSERO, number CRD42016048184.

Findings: 1512 full-text articles were independently screened for inclusion by two reviewers, from which 137 studies of 56 620 participants were included. 20 studies were assessed as being at low risk of bias for both random sequence generation and allocation concealment. There was weak evidence to suggest that cognitive behavioural interventions might reduce anxiety in primary and secondary settings. In universal secondary settings, mindfulness and relaxation-based interventions showed a reduction in anxiety symptoms relative to usual curriculum (SMD -0·65, 95% credible interval -1·14 to -0·19). There was a lack of evidence to support any one type of intervention being effective to prevent depression in universal or targeted primary or secondary settings. Comparison-adjusted funnel plots suggest the presence of small-study effects for the universal secondary anxiety analysis. Network meta-analysis was not feasible for wellbeing or suicidal ideation or self-harm outcomes, and results are reported narratively.

Interpretation: Considering unclear risk of bias and probable small study effects for anxiety, we conclude there is little evidence that educational setting-based interventions focused solely on the prevention of depression or anxiety are effective. Future research could consider multilevel, systems-based interventions as an alternative to the downstream interventions considered here.

Funding: UK National Institute for Health Research.

Figure 1

Study selection process Articles awaiting classification reasons are listed in the appendix (p 98).RCT=randomised controlled trial.

Figure 2

Network meta-analysis of eligible comparisons for depression and anxiety Depression (A) and anxiety (B). Width of solid black lines is proportional to the number of trials comparing each pair of interventions. Size of node (circle) is proportional to the number of randomly assigned participants receiving that intervention. CBT=cognitive behavioural therapy. IPT=interpersonal therapy. CBT SH=cognitive behavioural therapy self-help. Third wave=third wave CBT-based therapies.

Figure 3

Self-report depression and anxiety immediately post-intervention (A) Universal population. Active intervention is displayed relative to the reference intervention Usual Curriculum. (B) Targeted population. For targeted primary the reference intervention displayed is waiting list. For targeted secondary the reference is no intervention. Effect estimates are based on combination of direct and indirect evidence from a random effects network meta-analysis. Direct trials are the number of head-to-head trials in the network making that comparison. Solid black lines denote the depression outcome and the dashed lines denote the anxiety outcome. k=number of studies included in network meta-analysis. SMD=standardised mean difference. CrI=credible interval. CBT=cognitive behavioural therapy. IPT=interpersonal therapy.

Figure 3

Self-report depression and anxiety immediately post-intervention (A) Universal population. Active intervention is displayed relative to the reference intervention Usual Curriculum. (B) Targeted population. For targeted primary the reference intervention displayed is waiting list. For targeted secondary the reference is no intervention. Effect estimates are based on combination of direct and indirect evidence from a random effects network meta-analysis. Direct trials are the number of head-to-head trials in the network making that comparison. Solid black lines denote the depression outcome and the dashed lines denote the anxiety outcome. k=number of studies included in network meta-analysis. SMD=standardised mean difference. CrI=credible interval. CBT=cognitive behavioural therapy. IPT=interpersonal therapy.