Evidence for the continuum-severity model of psychosis through scrutiny of the architecture of symptoms associated with schizophrenia

Martin, Colin R.; Fleming, Mick

Abstract

The psychosis continuum provides a framework to develop a compelling insight into the architecture of psychotic experiences in non-clinical samples. Using schizophrenia specific measures within non-clinical samples offers further opportunity to investigate psychotic experiences and compare to those reported in clinical samples.
A cross sectional survey method was used to collect data from a non-clinical sample (n=510) using the Schizophrenia Quality of Life Scale-Revision 4 (SQLS-R4) and the Hospital Anxiety and Depression Scale (HADS).
Conducting confirmatory factor analysis and bi-factor modelling found that a bi-factor model offered a better model fit to the data than the established two factor model. A general factor explained most item variance whilst seven domain specific factors explained a further small amount of item variance. Participants with higher anxiety reported comparatively poorer QOL to those with lower anxiety. Comparison with data taken from a clinical sample found similarities in both the internal consistency and correlation coefficients between SQLS-R4 totals and sub-scales and HADS total scores and sub-scales.
These results show the presence of a robust general psychosis QOL factor within a non-clinical sample. The use of schizophrenia specific measures and bi-factor modelling can provide suitable methods for investigating the nature of the psychosis continuum.

Citation

Martin, C. R., & Fleming, M. (2019). Evidence for the continuum-severity model of psychosis through scrutiny of the architecture of symptoms associated with schizophrenia. Psychosis, 11(1), 42-53. https://doi.org/10.1080/17522439.2018.1545861

• Journal Article Type: Article
• Acceptance Date: Nov 6, 2018
• Online Publication Date: Dec 6, 2018
• Publication Date: 2019
• Deposit Date: Nov 29, 2018
• Publicly Available Date: Dec 7, 2019
• Print ISSN: 1752-2439
• Publisher: Routledge
• Peer Reviewed: Peer Reviewed
• Volume: 11
• Issue: 1
• Pages: 42-53
• DOI: https://doi.org/10.1080/17522439.2018.1545861
• Keywords: Dimensions; Severity continuum; Psychosis; Quality of life; Bi-factor model; Anxiety
• Public URL: https://hull-repository.worktribe.com/output/1164443
• Publisher URL: https://www.tandfonline.com/doi/full/10.1080/17522439.2018.1545861
• Contract Date: Nov 29, 2018