Neuropsychology, genetic liability, and psychotic symptoms in those at high risk of schizophrenia.

Neuropsychological assessments were compared among individuals at enhanced genetic risk of schizophrenia (n = 157) and controls (n = 34). The relationship between cognitive impairments and the presence of psychotic symptoms and measures of genetic risk was explored in the high-risk subjects. Neuropsychological differences were identified in many areas of function and were not accounted for by the presence of psychotic symptoms. Genetic liability was not associated with neuropsychological performance or with psychotic symptoms, but exploratory analysis showed some tests were associated with both liability measures. These results suggest that what is inherited is not the disorder itself but a state of vulnerability manifested by neuropsychological impairment, occurring in many more individuals than are predicted to develop the disorder.