Cognitive intraindividual variability, cognitive impairment and psychosocial functioning in first-episode psychosis patients

•Cognitive intraindividual variability is understudied in first episode psychoses.•Higher cognitive variability and worse global cognitive performance are associated.•Cognitive intraindividual variability is related to worse psychosocial functioning.•Cognitive intraindividual variability is independent of clinical status. Cognitive intraindividual variability (IIV) refers to fluctuations in performance across tasks (i.e. dispersion) or in a single task on multiple occasions (i.e. inconsistency). Little is known about IIV in patients with first-episode psychosis (FEP). We aimed to explore the association between IIV and both global cognitive performance and psychosocial functioning in a sample of 103 FEP patients. Patients were recruited at discharge from the PEPsNa program, a FEP follow-up intervention program lasting 24 months. The Social and Occupational Functioning Scale (SOFAS) and the Cognitive Assessment Interview (CAI-Sp) were employed for assessing psychosocial functioning. Cognitive assessments were performed using the MATRICS Cognitive Assessment Battery (MCCB), and the variability in the cognitive functions assessed with the MCCB was used to calculate the IIV. Significant correlations were obtained between IIV and global MCCB scores, the CAI-Sp and the SOFAS. We found significant differences in psychosocial functioning and cognitive performance between patients with high and low IIV. A higher IIV in FEP patients was related both to worse psychosocial functioning and worse global cognitive performance. Unlike global cognitive performance, IIV was not related to clinical characteristics, suggesting that it could be an indicator of cognitive impairment even in the absence of global impairment.