Cognitive improvement in first-episode schizophrenia and healthy controls: A 6-year multi-assessment follow-up study

Abstract

The development of individual cognitive domains over time is not yet fully examined in first-episode schizophrenia (FES). This study's objective was to explore the cognitive trajectories of FES-patients (n = 28) and compare them to a pairwise matched healthy control group (n = 28, total n = 56). This study has a multi-assessment design, and includes patient data from seven assessments over six years. Healthy controls were assessed at baseline, after two years and after six years. Cognition was assessed with the MATRICS Consensus Cognitive Battery. Data were analyzed with linear multilevel models. FES-patients scored significantly lower than the control group across all cognitive domains at baseline. Over six years, improvements were seen in attention, verbal learning, processing speed, reasoning/ problem solving, working memory and social cognition. The overall trend points toward a similar cognitive change in both groups. The patient group's improvement in reasoning/ problem solving was significantly larger that the control group, but improvement in working memory was smaller. Cognitive improvements were seen under and after the initial psychosis episode and throughout the recovery process with 45.5% of the patients fully recovered by 6-year follow-up. Cognitive improvements were seen in almost every cognitive domain that is consistently impaired in FES.