Do environmental risk factors for the development of psychosis distribute differently across dimensionally assessed psychotic experiences?

Russell G Foster,Guy M Goodwin,Iona Alexander,Jan Cosgrave,Dalena Van Heugten-Van Der Kloet,Ross Haines,Ross J Purple,Kate Porcheret,Louise Johns,Katharina Wulff

doi:10.1038/s41398-021-01265-2

Abstract

Psychotic experiences (PE) are associated with poorer functioning, higher distress and the onset of serious mental illness. Environmental exposures (e.g. childhood abuse) are associated with the development of PE. However, which specific exposures convey risk for each type or dimension of PE has rarely been explored. The Oxford Wellbeing Life and Sleep (OWLS) survey includes 22 environmental risk factors for psychosis and was designed to examine how environmental risks are associated with specific dimensions of PE. Multivariate logistic regression models were fit using these risk factors to predict six dimensions of PE (perceptual abnormalities, persecutory ideation, bizarre ideas, cognitive disorganisation, delusional mood and negative symptoms). Models were built using only 70% of the data, and then fit to the remaining data to assess their generalisability and quality. 1789 (27.2% men; mean age = 27.6; SD = 10.9) survey responses were analysed. The risk factors predictive of the most PE were anxiety, social withdrawal during childhood and trauma. Cannabis and depression predicted three dimensions with both predicting bizarre ideas and persecutory ideation. Psychological abuse and sleep quality each predicted two dimensions (persecutory ideation and delusional mood). Risk factors predicting one PE dimension were age (predicting cognitive disorganisation), physical abuse (bizarre ideas), bullying and gender (persecutory ideation); and circadian phase (delusional mood). These results lend support for a continuum of psychosis, suggesting environmental risks for psychotic disorders also increase the risk of assorted dimensions of PE. Furthermore, it advocates the use of dimensional approaches when examining environmental exposures for PE given that environmental risks distribute differently across dimensions.

Highlights

Psychotic experiences (PE) are symptoms deemed comparable to the positive symptoms of psychosis, but not sufficiently severe to warrant a diagnosis upon clinical presentation
Cross-sectional differences were explored across four predefined PE risk levels according to the number of psychotic experiences endorsed in the sample: (1) a PQ16 score of 0, indicating a very low risk; (2) a PQI6 score between 1 and 5, indicating minimal risk; (3) a PQ16 score above 5, indicating a moderate or ‘at-risk’ group; and (5) a PQ16 score above 5 and having sought help or experienced distress associated with these symptoms, indicating the highest risk group
Treatments and ethnicities are reported as percentages of the sample whereas the psychometric profile uses the mean or median score across a group. aShowed significant differences between risk levels. bPresented with a skewed distribution, as such, the median was used as a measure of central tendency

Summary

Introduction

Psychotic experiences (PE) are symptoms deemed comparable to the positive symptoms of psychosis, but not sufficiently severe to warrant a diagnosis upon clinical presentation. PE are prevalent (5.8–7%), signify a Several studies have shown that, consistent with diagnosed psychosis and schizophrenia, PE have a multidimensional structure[5,6]. The number and structure of the dimensions varies across studies (subject to analysis and measures)[6]. Genetic heritability has been shown to range from 33 to 57% depending on the dimension of PE. Allelic variants differ in the type of PE they confer the Cosgrave et al Translational Psychiatry (2021)11:226 greatest risk for 6,7. Dimensions vary in their severity, associated distress and risk for the development of further mental health difficulties[6]

Methods

Results

Discussion

Conclusion