The course of cognitive functioning over six months in individuals at clinical high risk for psychosis.

Cognitive impairment is common in psychosis and has recently been observed in individuals at clinical high risk (CHR) of developing psychosis. The purpose of this study was to characterize longitudinal change in cognition among CHR individuals, and compare cognition of CHR individuals who later convert to psychosis to that of CHR who do not convert. Participants were tested at baseline and followed-up after six months using a comprehensive cognitive test battery. Individuals who did not convert to psychosis either remained stable or significantly improved in their cognitive performance. At baseline participants who converted to psychosis compared to non-converters exhibited poorer performance in several cognitive tests, suggesting that some cognitive impairment is already present before conversion. Future longitudinal research should address if further decline takes place during the prodrome or after conversion to psychosis.