Testing the neurodevelopmental, trauma and developmental risk factor models of psychosis using a naturalistic experiment.

Yiwen Liu,Dieter Wolke,Marina Mendonça,Helen O'Reilly,Neil Marlow,Peter Bartmann,Samantha Johnson

doi:10.1017/s0033291719003349

Abstract

The neurodevelopmental and trauma theories are two widely cited models of psychosis. A third - the developmental risk factor model (DRFM) - recognises the combined role of neurodevelopmental risks and trauma. Our objective was to test these theories using preterm populations as a natural experiment, given the high prevalence of neurodevelopmental deficits and exposure to trauma. Two population-based preterm birth cohorts, the Bavarian Longitudinal Study (BLS; N = 399) and EPICure Study (N = 184), were included with term-born controls. Peer victimisation in childhood was assessed by parent and child report and psychotic experiences (PE) were assessed in early adulthood. Different models of psychosis were tested using regression and mediation analyses. There was support for the trauma and DRFM in the BLS. Peer victimisation increased the risk of PE for preterm and term-born participants equally [odds ratio = 4.87, 95% confidence interval (CI) 1.96-12.08]. There was an indirect effect where preterm children were more likely to be victimised, which subsequently increased risk of PE [β = 1.12 (s.e. = 0.61), 95% CI 0.11-2.48]. The results were replicated in EPICure. Exposure to trauma which is experienced more often by neurodevelopmental risk children rather than neurodevelopmental risk per se increases the risk of PE. The findings are consistent with the trauma model and DRFM. Interventions focused on reducing trauma may reduce the development of PE.

Highlights

A range of theories have been proposed to explain the aetiology or development of psychosis but have been difficult to test as clinically diagnosed psychosis is rare (3% across the lifetime) (van Os et al 2009)
There is increasing evidence that factors found to be associated with psychosis are associated with psychotic experiences (PE) supporting their use in population studies (Johns & Os 2001)
Brain lesions are difficult to study in large population studies motor, cognitive and behavioural abnormalities in childhood prior to the onset of psychosis are often considered as intermediate phenotypes, with evidence of these abnormalities reported in previous studies (Jones et al 1994; Pantelis et al 2003; Dean et al 2018)

Summary

Introduction

A range of theories have been proposed to explain the aetiology or development of psychosis but have been difficult to test as clinically diagnosed psychosis is rare (3% across the lifetime) (van Os et al 2009). Brain lesions are difficult to study in large population studies motor, cognitive and behavioural abnormalities in childhood prior to the onset of psychosis are often considered as intermediate phenotypes, with evidence of these abnormalities reported in previous studies (Jones et al 1994; Pantelis et al 2003; Dean et al 2018). These neurodevelopmental impairments are frequent after low birth weight and premature birth and have been found to increase the risk of psychosis in adulthood (Byrne et al 2007; Nosarti et al 2012). Our objective was to test these theories using preterm populations as a natural experiment, given the high prevalence of neurodevelopmental deficits and exposure to trauma

Objectives

Methods

Results

Conclusion