Longitudinal profiles of neurocognitive function in first-episode pyschosis

Abstract

Neurocognitive impairments in schizophrenia have been reported in numbers of studies. While some studies suggest global impairments in these patients, others demonstrated specific impairments. Implications of many previous studies were limited by methodological issues, such as recruitment of chronic cases and cross-sectional designs. In order to further investigate the cognitive profile in psychotic disorders, this study adopted a prospective design with an original sample of 153 patients with first-episode psychosis (FEP), out of which 90 were available for analysis up to 20-month follow-up. A set of neurocognitive tests, including attention (Continuous Performance Test), memory (Logical Memory, Visual Reproduction, Digit Forward Span), as well as executive function (Verbal Fluency, Wisconsin Card Sorting Test)., were carried out upon admission, discharge, and every 4 months up to 20 months. Results showed that patients as a group showed impairment in various domains but improvement over time was evident. In particular, two patterns of longitudinal performance were exhibited: (1) Performance on neurocognitive tests involving semantic components (logical memory and verbal fluency) tended to remain within a mild impairment range; (2) Performance on tests in which semantic components were not involved tended to improve over time and then level off within normal range. This suggests that neurocognitive functions in patients with FEP are generally impaired during the first episode. Most of these impairments improve with time, but those in which semantic components are involved are less likely to revert to normal level.