Personality traits across the psychosis continuum: an in-depth quantitative research.

Abstract

Background: It has been proposed that psychotic experiences exist on a continuum, ranging from healthy individuals, through frequent psychotic experiences (PE) in non-clinical individuals, to severely psychotic patients. This study aims to conduct an in-depth investigation into the differences in personality traits and its underlying facets in psychotic patients, non-clinical individuals with psychotic experiences and healthy controls. Methods: The study assessed 40 psychotic patients, 134 non-clinical individuals with PE and 125 healthy controls. All participants completed the Dutch versions of the NEO-PI-R. ANOVAs were performed in order to investigate the differences in the levels of personality traits and facets, between the three groups. Results: The results revealed significant differences between the three groups in the domains of Neuroticism, Openness and Conscientiousness, with the highest levels of Neuroticism and the lowest level of Conscientiousness in patients as compared to both non-clinical individuals with PE and healthy controls. Also, non-clinical individuals with PE showed the highest level of Openness, as compared to both patients and healthy controls. Furthermore, facet-level analyses showed significant differences between the three groups in five facets of Neuroticism, four facets of Openness and three of facets Conscientiousness. Exploratory analyses showed significant differences in two facets of Extraversion and one facet of Agreeableness. Discussion: This is the first study in the field of schizophrenia investigating personality domains and facets in such depth, revealing distinctive personality profiles in patients and non-clinical individuals with PE. These results provide more insight in which personality characteristics function as protective or risk factors for developing psychosis. This could complement health care in developing prevention and treatment programs for psychosis.