Investigating the effectiveness of three school based interventions for preventing psychotic experiences over a year period - a secondary data analysis study of a randomized control trial

Abstract

Introduction: Psychotic experiences (PEs) are associated with increased risk of later mental disorders and so could be valuable in prevention studies. However, to date few intervention studies have examined PEs. Given this lack of evidence, in the current study a secondary data analysis was conducted on a clustered-randomized control trial (RCT) of 3 school based interventions to reduce suicidal behaviour, to investigate if these may reduce rates of PEs, and prevent PE, at 3-month and 1-year follow-up.

Methods: The Irish site of the Saving and Empowering Young Lives in Europe study, trial registration (DRKS00000214), a cluster-RCT designed to examine the effect of school-based interventions on suicidal thoughts and behaviour. Seventeen schools (n = 1096) were randomly assigned to one of three intervention arms or a control arm. The interventions included a teacher training (gate-keeper) intervention, an interactive educational (universal-education) intervention, and a screening and integrated referral (selective-indicative) intervention. The primary outcome of this secondary data-analysis was reduction in point-prevalence of PEs at 12 months. A second analysis excluding those with PEs at baseline was conducted to examine prevention of PEs. Additional analysis was conducted of change in depression and anxiety scores (comparing those with/without PEs) in each arm of the intervention. Statistical analyses were conducted using mixed-effects modelling.

Results: At 12-months, the screening and referral intervention was associated with a significant reduction in PEs (OR:0.12,95%CI[0.02-0.62]) compared to the control arm. The teacher training and education intervention did not show this effect. Prevention was also observed only in the screening and referral arm (OR:0.30,95%CI[0.09-0.97]). Participants with PEs showed higher levels of depression and anxiety symptoms, compared to those without, and different responses to the screening and referral intervention & universal-education intervention.

Conclusions: This study provides the first evidence for a school based intervention that reduce & prevent PEs in adolescence. This intervention is a combination of a school-based screening for psychopathology and subsequent referral intervention significantly reduced PEs in adolescents. Although further research is needed, our findings point to the effectiveness of school-based programmes for prevention of future mental health problems.

Keywords: Intervention; Prevention; Psychosis; Psychotic experiences; School based intervention.

Fig. 1

CONSORT diagram of the Irish site of the SEYLE study. (Note: Grey shading indicates the intervention period. Partial PEs data indicates the number of individuals who provided at least one wave of PEs data. These individuals were included in the main analysis. A supplementary analysis restricted to participants who provided data at all three waves of the study is presented in eAnalysis 1)

Fig. 2

The point prevalence of psychotic experiences at baseline, 3-months and 12-months follow-up in each arm of the study. (Note: Dotted line is the point prevalence in each of the participating schools. Grey shading indicates the intervention period)

Fig. 3

Depression scores at baseline, 3-months and 12-months follow-up in each arm of the study when stratified by the presence or absence of psychotic experiences at baseline. (Note: Beck depression Inventory. Grey shading indicates the intervention period. Dotted lines are linear trend lines. Error bars represent +/-1 standard error of the mean)

Fig. 4

Anxiety scores at baseline, 3-months and 12-months follow-up in each arm of the study when stratified by the presence or absence of psychotic experiences at baseline. (Note: Zung Anxiety Score. Grey shading indicates the intervention period. Dotted lines are linear trend lines. Error bars represent +/-1 standard error of the mean)