The aim of this study within the Athens Study of Psychosis Proneness and Incidence of Schizophrenia (ASPIS) was the examination of the latent structure of schizotypal dimensions among a large population of young male conscripts in the Greek Air Force during their first week of military training. Confirmatory factor analysis (CFA) was conducted on 1,355 reliable responders to the self-rated Schizotypal Personality Questionnaire (SPQ), which covers all nine aspects of DSM-III-R schizotypal personality disorder (SPD). A four-factor model (cognitive/perceptual, paranoid, negative, and disorganization schizotypal dimensions) provided a better fit to the data than did other competing models (one-, two-, three-, four, and five-factor models). This result is in agreement with recent findings supporting the notion of a multidimensional construct of the schizotypy and related schizophrenia phenotype.

Background: Exposure to stressful life events increases the risk of developing a psychotic disorder. Moreover, increased reactivity to stress seems to represent part of the vulnerability for psychosis. This study aimed to investigate whether a functional polymorphism in the catechol-O-methyltransferase (COMT Val¹⁵⁸Met) gene moderates the psychosis-inducing effects of stress.Method: A semi-experimental stress exposure paradigm was used in a sample of 306 genotyped young men (aged 19–24 years), in whom measures of psychotic symptoms were obtained at recruitment in the Greek army (exposed condition) and again after 18 months of military training (unexposed condition).Results: Stress exposure at army induction was associated with an increased level of psychotic symptoms. In addition, carriers of the COMT Val¹⁵⁸Met Val allele were more susceptible to the effect of stress on the psychosis outcome than those with the Met/Met genotype (test for interaction: χ²=5·02, df=1, p=0·025).Conclusion: The COMT Val¹⁵⁸Met genotype may moderate the effect of stress on psychotic symptoms.