Associations between age and neurocognition in individuals at clinical high risk and first-episode psychosis.

Neurocognitive deficits differ with age during the early stages of psychosis. This study aimed to explore age-related differences (9-35 years old) in the neurocognitive performance of a large clinical population. In total, 1059 individuals with first-episode psychosis (FEP), 794 individuals with a clinical high risk of psychosis (CHR), and 774 well-matched healthy controls (HC) were recruited between 2016 and 2021. Neurocognitive assessments were performed using the Chinese version of the Measurement and Treatment Research to Improve Cognition in Schizophrenia Battery(MCCB). The MCCB subtest scores differed significantly among the groups across the age span. The mean scores of subtests in CHR individuals were approximately one standard deviation(SD) lower than that of HC, while that of FEP patients was approximately two SDs. The adolescents performed better than the adults in the HC, CHR, and FEP groups. In the HC group, a stronger correlation was found between age and cognitive function, and more neurocognitive domains were affected by age than in the CHR and FEP groups. These results emphasize that neurocognitive deficits in psychosis are present at the pre-onset stage and deteriorate at the first-episode stage across the age span, implicating the development of specific strategies that could monitor the cognitive trajectory in early psychosis.