Correlates of psychosis proneness in relatives of schizophrenic patients

The Magical Ideation Scale (MIS), Perceptual Aberration Scale (PABS), Social Anhedonia Scale (SAS), and Physical Anhedonia Scale (PAS) were administered to 98 relatives of schizophrenic patients along with a measure of personality disorders (the Personality Diagnostic Questionnaire--Revised). Hierarchical regression analysis indicated that the schizotypal and borderline personality disorder (PD) scales explained significant variance in both the MIS and PABS; the avoidant PD scale also explained significant variance in the PABS. The schizoid, paranoid, and avoidant PD scales explained significant variance in the SAS. Sibling intraclass correlations indicated a significant heritability of 0.62 for the PABS.