Affective temperament-based personality traits such as neuroticism have been found to be related to schizophrenia and schizotypy. However, studies thus far have not clarified the differential association of neuroticism with individual schizotypy dimensions and the role it plays in the expression of schizophrenia-spectrum phenomena.

204 nonclinically ascertained participants completed self-report questionnaires assessing neuroticism and the positive and negative schizotypy dimensions, and underwent structured interviews assessing schizophrenia-spectrum psychopathology (psychotic-like experiences, negative symptoms, cluster A personality disorders), mood episodes, substance abuse, and global functioning.

Results indicated that neuroticism predicted positive symptoms of schizophrenia and depression, over and above the effects of both schizotypy dimensions. Also, neuroticism moderated the association of positive schizotypy with interview measures of psychopathology and functioning.

The results of this study support other research indicating that neuroticism is etiologically relevant for spectrum psychopathology and that it cannot be considered solely a ‘secondary effect’ of spectrum disorders. Current psychological models of psychosis can accomodate the finding of neuroticism being a shared vulnerability factor for affective and psychotic disorders.