Neurocognitive trajectories and their clinical implications in first-episode schizophrenia after one year of antipsychotic treatment

Neurocognitive impairment is a core feature of schizophrenia, and patients with first-episode schizophrenia (FES) are optimal candidates for cognitive remediation, but we do not know enough about the incidence, severity and longitudinal changes in neurocognitive impairment in those with FES. This study aimed to assess the neurocognitive trajectories of patients with FES and to compare the clinical and functional outcomes among those with different trajectories. A total of 562 untreated patients with FES completed a neurocognitive test battery and psychopathological and functional assessment. A total of 373 patients attended the follow-up. Group-based trajectory modelling (GBTM) was applied to identify neurocognitive trajectories. Analysis of variance and chi-square tests were conducted to compare demographic characteristics, multiple neurocognitive domains, and clinical and functional outcomes among the different subgroups. We identified three neurocognitive subgroups: preserved (n = 133), mildly to moderately impaired (n = 187) and severely impaired (n = 53). Neurocognitive function in the two impaired subgroups improved within a year but failed to reach the normal level. The processing speed followed trajectories similar to those of overall cognition. The three subgroups did not significantly differ in antipsychotic usage or clinical remission rate. The severely impaired subgroup had poorer functional outcomes than the preserved subgroup, but the mildly to moderately impaired subgroup did not. Patients with FES followed distinct neurocognitive trajectories during the first year of treatment. Patients with severe neurocognitive impairment have poorer functional outcomes, which require and are more likely to benefit from cognitive remediation. Processing speeding is a potential indicator for screening overall cognition.