Neuropsychological status of subjects at high risk for a first episode of psychosis.

Thirty-six subjects aged 16 years or older judged at risk for a first episode of psychosis within a North American multi-site study of the schizophrenia prodrome [McGlashan et al., Schizophr. Res. (2003); Miller et al., Schizophr. Res. (2003)] performed at levels intermediate to population norms and data reported for schizophrenia samples on a comprehensive neuropsychological exam. In the context of normal intelligence, this intermediate status suggests that, as a group, these subjects are not fully normal in neuropsychological functioning. Conversely, the finding that they do not show the levels of impairment commonly observed in schizophrenia, including within the first episode, suggests that prodromal interventions might conceivably prevent, delay, or lessen the severity of declines associated with first psychotic episodes.