BACKGROUND - Schizotypy is a range of perceptual experiences and personality features related to risk and familial predisposition to psychosis. Despite evidence that schizotypy is related to psychosis vulnerability, very little is known about the expression of schizotypal traits in individuals with a psychotic disorder, and their relationship to clinical symptoms, cognition, and psychosocial functioning.
METHODS - 59 healthy subjects and 68 patients with a psychotic disorder (47 schizophrenia spectrum disorder; 21 bipolar disorder with psychotic features) completed four schizotypy scales, the Perceptual Aberration Scale, the Revised Physical and Social Anhedonia Scales, and the Schizotypal Personality Questionnaire, a brief neuropsychological assessment, and a self-report measure of quality of life. Clinical symptoms of psychosis were quantified in patients with the Positive and Negative Syndrome Scale (PANSS).
RESULTS - Psychosis patients scored higher than healthy subjects on all schizotypy scales. Correlations between schizotypy and PANSS scores were modest, ranging from r=.06 to r=.43, indicating that less than 20% of the variance in self-reported schizotypy overlapped with clinical symptoms. After controlling for clinical symptoms, patients with schizophrenia spectrum disorders reported higher levels of cognitive-perceptual disturbances and negative traits than patients with bipolar disorder. Elevated schizotypy was associated with lower cognitive functioning and self-reported quality of life.
CONCLUSIONS - Schizotypal personality traits are markedly elevated in psychotic disorders, especially schizophrenia spectrum disorders, relatively weakly correlated with positive and negative psychotic symptoms, and associated with greater cognitive impairment and lower quality of life. Assessing schizotypy in patients with psychosis may be useful for predicting functional outcome and differential diagnosis.
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