Neurocognitive functioning in patients with first-episode schizophrenia 1 year from onset in comparison with patients 5 years from onset.

Abstract

OBJECTIVE: The course of neurocognitive deficits in schizophrenia has not yet been established. Therefore, we followed patients with first-episode schizophrenia to verify the course of these deficits. METHODS:In Study 1, tests of neurocognitive functioning were administered to patients with first-episode schizophrenia (FE group) every 6 months. Of the 26 patients who completed the baseline assessment, 19 completed a 6-month follow-up, and 13 completed a 1-year follow-up. In Study 2, 19 patients in FE group at 6-months when the neuropsychological measures was less influenced by psychotic symptoms and other patients who experienced schizophrenia 5-years earlier (5-year group) were compared. RESULTS:In Study 1, verbal memory, motor speed, and executive functions significantly improved at the 1-year follow-up. In Study 2, patients in 5-year group performed worse in verbal memory and executive functions than patients in FE at 6-month group, but marginally but significantly better in verbal fluency. CONCLUSIONS:Verbal memory, executive functions, and verbal fluency were significantly different between 5-year group and FE at 6-month group, and may indicate progression of schizophrenia. Executive functions may reflect the state of psychosis. Working memory and processing speed which did not change significantly from onset are needed to verify the course in further research.