Cognitive functioning in stabilized first-episode psychosis patients

This paper describes the cognitive functioning of a community cohort of individuals presenting with a first episode of a schizophrenia spectrum psychosis. Data were obtained for 107 patients (mean age 25 years) following stabilization of acute psychotic symptoms, mostly with the use of novel antipsychotics, on measures of intellectual, memory, attentional and executive functioning using a standardized battery of cognitive measures, including WAIS III and WMS III. While patients generally performed in the average range across the majority of measures, deficits (Z-scores >1.0 S.D.) were observed on measures of speed of information processing (PASAT, WAIS III) and executive functions (Stroop Test and Trails B), with the greatest deficits observed on tests of processing speed (PASAT). Discrepancy scores between the NART and the WAIS suggest subtle but statistically significant declines in full scale and performance IQ following onset of psychosis. Differences in cognitive functioning between diagnostic groups were not supported. Comparison of the highest and lowest functioning patients with respect to the cognitive measures also did not support any demographic or clinical differences between these two subgroups. Our results suggest a relatively benign cognitive profile in first-episode schizophrenia spectrum psychosis, regardless of diagnosis, when most potential incidence cases in the community are included. The most severe deficits reported were on measures of speeded information processing, and level of performance did not distinguish between patients demographically or clinically.