Neuropsychological functioning in first-episode psychosis - evidence of specific deficits

Neuropsychological impairment is ubiquitous in schizophrenia even at the fi rst presentation of psychotic symptoms. We sought to elucidate the nature o f the neuropsychological profile at the onset of the illness by examining t he neuropsychological functioning of 40 patients experiencing their first e pisode of psychosis and 22 matched controls. All participants completed a b attery of neuropsychological tasks designed to assess attention, verbal lea rning/memory, non-verbal memory, spatial ability, psychomotor speed, and ex ecutive function. First-episode patients showed significant impairment on t asks of executive function, including those requiring the ability to form a nd initiate a strategy, to inhibit prepotent responses, and to shift cognit ive set, and also on tasks of verbal fluency. Memory impairments were seen on verbal learning and delayed non-verbal memory only, impairment on tasks of psychomotor speed suggests that there may be a significant amount of cog nitive slowing even at the first onset of psychosis. We suggest that our pa tients may be experiencing difficulty in specific aspects of executive func tions, including the ability to form and execute a strategy, and these diff iculties may be mediating the deficits observed on tasks of verbal learning . (C) 2000 Elsevier Science B.V. All rights reserved.