Prevention of self-harm and suicide in young people up to the age of 25 in education settings

Background: In 2016, globally, suicide was the second leading cause of death amongst those aged 15 to 29 years. Self-harm is increasingly common among young people in many countries, particularly among women and girls. The risk of suicide is elevated 30-fold in the year following hospital presentation for self-harm, and those with suicidal ideation have double the risk of suicide compared with the general population. Self-harm and suicide in young people are significant public health issues that cause distress for young people, their peers, and family, and lead to substantial healthcare costs. Educational settings are widely acknowledged as a logical and appropriate place to provide prevention and treatment. A comprehensive, high-quality systematic review of self-harm and suicide prevention programmes in all education settings is thus urgently required. This will support evidence-informed decision making to facilitate rational investment in prevention efforts in educational settings. Suicide and self-harm are distressing, and we acknowledge that the content of this review is sensitive as the data outlined below represents the lived and living experience of suicidal distress for individuals and their caregivers.

Objectives: To assess the effects of interventions delivered in educational settings to prevent or address self-harm and suicidal ideation in young people (up to the age of 25) and examine whether the relative effects on self-harm and suicide are modified by education setting.

Search methods: We searched the Cochrane Common Mental Disorders Specialised Register, CENTRAL, The Cochrane Database of Systematic Reviews, Ovid MEDLINE, PsycINFO, ERIC, Web of Science Social Science Citation Index, EBSCO host Australian Education Index, British Education Index, Educational Research Abstracts to 28 April 2023.

Selection criteria: We included trials where the primary aim was to evaluate an intervention specifically designed to reduce self-harm or prevent suicide in an education setting. Randomised controlled trials (RCTs), cluster-RCTs, cross-over trials and quasi-randomised trials were eligible for inclusion. Primary outcomes were self-harm postintervention and acceptability; secondary outcomes included suicidal ideation, hopelessness, and two outcomes co-designed with young people: better or more coping skills, and a safe environment, with more acceptance and understanding.

Data collection and analysis: We used standard methodological procedures as expected by Cochrane. Two review authors independently selected studies, extracted data, and assessed risk of bias. We analysed dichotomous data as odds ratios (ORs) and continuous data as standardised mean differences (SMDs) with 95% confidence intervals (CIs). We conducted random-effects meta-analyses and assessed certainty of evidence using the GRADE approach. For co-designed outcomes, we used vote counting based on the direction of effect, as there is a huge variation in the data and the effect measure used in the included studies.

Main results: We included 51 trials involving 36,414 participants (minimum 23; maximum 11,100). Twenty-seven studies were conducted in secondary schools, one in middle school, one in primary school, 19 in universities, one in medical school, and one across education and community settings. Eighteen trials investigated universal interventions, 11 of which provided data for at least one meta-analysis, but no trials provided data for self-harm postintervention. Evidence on the acceptability of universal interventions is of very low certainty, and indicates little or no difference between groups (OR 0.77, 95% CI 0.36 to 1.67; 9 studies, 8528 participants). Low-certainty evidence showed little to no effect on suicidal ideation (SMD -0.02, 95% CI -0.23 to 0.20; 4 studies, 379 participants) nor on hopelessness (MD -0.01, 95% CI -1.98 to 1.96; 1 trial, 121 participants). Fifteen trials investigated selective interventions, eight of which provided data for at least one meta-analysis, but only one trial provided data for self-harm postintervention. Low-certainty evidence indicates that selective interventions may reduce self-harm postintervention slightly (OR 0.39, 95% CI 0.06 to 2.43; 1 trial, 148 participants). While no trial provided data for hopelessness, little to no effect was found on acceptability (OR 1.00, 95% CI 0.5 to 2.0; 6 studies, 10,208 participants; very low-certainty evidence) or suicidal ideation (SMD 0.04, 95% CI -0.36 to 0.43; 2 studies, 102 participants; low-certainty evidence). Seventeen trials investigated indicated interventions, 14 of which provided data for at least one meta-analysis, but only four trials provided data for self-harm postintervention and two reported no events in both groups. Low-certainty evidence suggests that indicated interventions may slightly reduce self-harm postintervention (OR 0.19, 95% CI 0.02 to 1.76; 2 studies, 76 participants). There is also low-certainty evidence indicating that these interventions may decrease the odds of non-suicidal self-injury (OR 0.65, 95% CI 0.24 to 1.79; 2 studies, 89 participants). Evidence of a slight decrease in acceptability in the intervention group is of low certainty (OR 1.44, 95% CI 0.86 to 2.42; 10 studies, 641 participants). Low-certainty evidence shows that indicated interventions may slightly reduce suicidal ideation (SMD -0.33, 95% CI -0.55 to -0.10; 10 studies, 685 participants) and may result in little to no difference in hopelessness postintervention (SMD -0.27, 95% CI -0.55 to 0.01; 6 studies, 455 participants). There were mixed findings regarding the effect of suicide prevention interventions on a range of constructs relevant to coping skills and safe environment. None of the trials, however, measured the impact of improvements in these constructs on self-harm or suicidal ideation.

Authors' conclusions: While this review provides an update on the evidence about interventions targeting self-harm and suicide prevention in education settings, there remains significant uncertainty about the impact of these interventions. There are some promising findings but large replication studies are needed, as are studies that examine the combination of different intervention approaches, and can be delivered in a safe environment and implemented over a long period of time. Further research is required to understand and measure outcomes that are meaningful to young people with lived experience, as they want coping skills and safety of the environment in which they conduct their everyday lives to be measured as key outcomes in future trials.