Cognitive deficits in subjects at risk for psychosis, first-episode and chronic schizophrenia patients

Background: Identifying the types and characteristics of cognitive deficits before the onset of schizophrenia and during its subsequent course could improve early detection and contribute to our understanding of the evolution of the core behavioral deficits underlying this disorder. Methods: This study used the Measurement and Treatment Research to Improve Cognition In Schizophrenia (MATRICS) battery to identify cognitive deficits and their progression during the course of schizophrenia from genetic high risk (HRF) subjects, subjects with prodromal symptoms (prodromal), and patients with first episode (FSCZ) and multi-episode (CSCZ) schizophrenia, compared to controls, in a Chinese Han population of 267 subjects. Results: There were statistically significant cognitive deficits which first appeared in prodromal subjects which were also present in FSCZ and CSCZ. There were no statistically significant differences between controls and HRF on any cognitive measure. Deficits in Visual Learning, Speed of Processing, and Overall Cognition were significantly correlated with some symptom measures on PANSS or SIPS. There were no statistically significant differences in cognitive deficits between FSCZ and CSCZ, and on most measures the patients with schizophrenia did not show a progression to more severe cognitive deficits than the prodromal subjects. Conclusions: In this sample of Chinese subjects, prodromal subjects showed significant cognitive deficits which were similar in most domains to those found in patients with schizophrenia. Whether the pattern of cognitive deficits on the MATRICS battery found in prodromal subjects will help predict conversion to diagnosed schizophrenia or other psychotic disorders would help determine how useful this profile of cognitive deficits is as a potential endophenotype for schizophrenia.