Relationships between cognitive and neurological performance in neuroleptic-naive psychosis

The authors explored relationships between neuropsychological performance and neurological exam abnormalities in 86 never-medicated patients with nonorganic psychosis (59 with schizophrenia or schizoaffective disorder) and 51 healthy subjects. Assessments include a reliable subset of the Neurological Evaluation Scale (rNES) and several neuropsychological tests of attention, executive function, memory, and current and premorbid intelligence. Principal components analysis of the rNES yielded two main factors. Of these, CogPer (consisting of more cognitively demanding perceptual tasks) showed stronger relationships than RepMot (consisting of repetitive manual motor tasks) to neuropsychological measures. Customarily, frontal neuropsychological tasks also relate more strongly to CogPer than to RepMot. Approximately one-half of the variability in these cognitive and neurological assessments is shared.