Sex versus gender differences in schizophrenia: The case for normal personality differences.

Schizophrenia has generally been viewed as having a unique preschizophrenia personality or destructive to the personality post-onset. This view is reflected in the scarcity of studies of personality in schizophrenia with the exception of schizotypal personality considered by many as an endophenotype of schizophrenia. What is missing is the study of personality as independent of schizophrenia and as a potential source of schizophrenia heterogeneity. In this study we examine sex versus gender as an initial effort to introduce personality as a normal variant that influences how schizophrenia is expressed. Gender, a personality construct, was associated with the presence of depression in a large sample of schizophrenia patients controlling for sex, age of onset, severity of disorder, and education. The results suggest that gender, rather than sex, as a representative personality trait may yield important insights into how schizophrenia is expressed.