Predicting real-world functioning in outpatients with schizophrenia: Role of inflammation and psychopathology

•Negative symptoms are key determinants of poor real-world functioning in schizophrenia.•The inflammatory parameter IL-2 seems to be a biomarker of functional impairment.•Baseline functioning and cognitive performance predict functioning at one-year follow-up. Several studies indicate that negative and cognitive symptoms are determining factors of functioning in patients with schizophrenia. However, they do not usually include biological aspects, such as inflammatory markers. The current prospective study aims to identify clinical and biological factors predicting real-world functioning, at baseline and at one-year follow-up, of outpatients in an early stage of schizophrenia. Sample consist of 73 clinically stable patients with schizophrenia, of which 57 completed the one-year follow-up. Accurate psychopathology, functioning, and cognitive assessments were performed at baseline and follow-up (Positive and Negative Syndrome, Brief Negative Symptom, Calgary Depression, Personal and Social Performance Scales, and MATRICS Cognitive Consensus Battery). Biological biomarkers including anthropometric data and blood parameters were collected. Pearson correlation and multiple regression analyses including potential confounding factors were performed. Negative symptoms (especially asociality and avolition), along with the inflammatory biomarker interleukin-2, are the most important determining factors of poor real-world functioning in early-stage schizophrenia. The previous functioning, along with baseline cognitive performance in attention and vigilance, predicts functioning at one-year follow-up in these patients. Strategies aimed at improving negative and cognitive symptoms, as well as modifying certain inflammatory pathways, should be the targets to achieve functional recovery in the first years of schizophrenia.