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.