The relationship between childhood trauma and schizotypy and the pathways underlying this association

There is a growing body of literature demonstrating an association between childhood trauma and schizotypy (e.g. Afifi et al. 2011;Myin-Germeys et al. 2011). However, more research is required to build on methodological limitations of previous studies, explore the possible differential effects of specific trauma types and expand the focus from a single contributor (e.g. psychological, biological) by considering the additive/interactive contributors to schizotypal symptomatology. The aim of the thesis was to explore the relationship between a range of childhood traumatic experiences and schizotypy whilst also incorporating several social, psychological and genetic factors underlying these relationships. Participants were recruited as a part of a cross-sectional case-control study conducted in the London Boroughs of Lambeth and Southwark. The thesis covers a subsample of controls (N=212), healthy volunteers, aged 18-64 and residents in the same geographical area. Data were gathered using an in-depth standardised interview regarding childhood abuse (Childhood Experience of Care and Abuse - CECA) and The Structured Interview for Schizotypy – Revised (SIS-R) measuring a range of schizotypal symptoms and signs. The study found a linear association of total trauma and schizotypy (adj. β=.88, p=0.004), with the strongest associations observed for psychological (adj. OR=4.85, p=0.039) and physical abuse (adj. OR=3.56, p=0.003). These particular types of trauma had an especially robust effect on positive schizotypal traits (psychological: adj. OR=3.79, p=0.013; physical abuse: adj. OR=2.32, p=0.042), which are attenuated forms of positive symptoms of schizophrenia (e.g. hallucinations, delusions). Negative beliefs about self/others and depression were the main mediators of these associations. A strong relationship was found for genetic risk of psychosis and increased schizotypy (adj. β=3.41, p=0.015). Other moderators of the childhood trauma - schizotypy association were intrusive life events (adj. β=4.20, p=0.045). This study provides further insights into the association between childhood trauma and schizotypy and gives clues to pathways underlying this association