Sarah Bendall1,2, Tom Bailey3, Carol Hulbert3, Ana Garcia-Sanchez4, Emma Barlow5, Mario Alvarez-Jimenez1,2; 1Orygen: The National Centre of Excellence in Youth Mental Health, 2The Centre for Youth Mental Health, University of Melbourne, 3School of Psychological Sciences, University of Melbourne, 4Hospital Universitario de Gran Canaria, 5Clinical Services, Port Phillip Prison
Introduction: Childhood trauma is a risk factor for the development of psychosis. Theories propose specific mechanisms by which childhood trauma may contribute to more severe positive and negative psychotic symptoms, some of which are supported empirically. The robustness of this evidence is unclear due to mixed results and methodological limitations of individual studies. A systematic review and meta-analysis of the evidence for associations between childhood trauma and severity of hallucinations, delusions and negative psychotic symptoms in groups with psychotic disorder is needed. Method: A systematic search was conducted. Reference lists of relevant review papers were hand-searched, and authors contacted for data and additional unpublished studies. Study reporting bias and quality was assessed. Results: In total, 6667 studies were identified and of these 41 studies met inclusion criteria. Of these, 29 studies (4680 participants) were meta-analysed. Among individuals with psychosis, childhood trauma was significantly correlated with severity of hallucinations (r = .199, p < .001) and delusions (r = .172, p < .001) but not correlated with severity of negative symptoms (r = .049, p = .095). Severity of childhood neglect was correlated with negative symptoms (r = .142, p = .005). Conclusion: The results have important implications for early psychosis treatment. Childhood trauma should be assessed for routinely in early psychosis and interventions developed to treat hallucinations and delusions using trauma-focussed interventions. More research and training in how to assess and treat the effects of trauma sensitively and effectively is essential to the delivery of trauma-informed services for early psychosis.