Background: Broadening our knowledge of the relationship between personality and psychopathological dimensions in psychosis would provide insights into the nature of their underlying pathophysiology. Research, to date, has been carried out in chronic samples and the possibility that the personality assessment may have been contaminated by the psychotic episode cannot be ruled out. The aim of this study was to examine the relationships between personality and psychopathology in a 'first-episode psychosis' sample using a dimensional approach.
Method: Premorbid personality dimensions of 94 consecutively admitted 'first-episode psychosis' patients were assessed through the information collected from parents or a close biological relative. A semi-structured interview (Premorbid Assessment Schedule; [Tyrer, P., 1988. Personality Disorders: Diagnosis, management and course. Wright, London]) was used by a rater, blind to the patients' psychopathological symptoms. Associations between dimensions of premorbid personality and psychopathology were examined through Pearson correlation coefficients.
Results: The negative dimension was strongly associated with higher scores on the schizoid dimension. Additionally, trends towards significant direct associations were found between the negative dimension and both the passive-dependent and the schizotypic dimensions, between the hostility/suspiciousness dimension and both sociopathic and passive-dependent dimensions, and between the manic dimension and the obsessional dimension. Canonical correlation analysis demonstrated that premorbid personality dimensions explained 17% of the variance of psychopathological dimensions.
Conclusions: Our results suggest that premorbid personality dimensions may shape the expression of psychosis. Moreover, we hypothesize that certain personality dimensions, such as the schizoid dimension, should be considered nonspecific risk factors for expression of higher levels of negative symptomatology at the beginning of psychosis.