Validation of the Italian version of the Davos Assessment of Cognitive Biases Scale (DACOBS) in a sample of schizophrenia spectrum disorder patients and healthy controls.

PURPOSE Recently two instruments were developed to address the study of the cognitive biases in schizophrenia spectrum disorders (SSD): the Cognitive Biases Questionnaire for Psychosis (CBQ-P) and the Davos Assessment of Cognitive Biases Scale (DACOBS). Aim of this study was to validate the Italian version of the DACOBS. METHODS We investigated factor structure, reliability, discriminative and convergent validity of the instrument by comparing to the CBQ-P in an Italian sample of 102 patients diagnosed with SSD and 330 healthy controls (HC), matched by age, education and gender. RESULTS The second-order seven-factor solution provided the best results among the four models tested. Reliability proved to be very satisfactory, with ω coefficient ranged from 0.75 for Jumping to conclusions to 0.89 for Safety Behavior. The Italian version of DACOBS could discriminate psychosis from HC (Wilks' Lambda=0.64, F=34.284, p<0.001; h2=0.364). All seven DACOBS subscales were significantly correlated with the CBQ-P subscales (total sample: r=0.331-0.707; SSD group: r=0.424-0.735; HC group: r=0.177-0.460). CONCLUSIONS The Italian version of DACOBS is a valid instrument for measuring cognitive biases for patients with psychosis, confirming previous results regarding the psychometric properties of the tool.