Factor Congruence and Psychometric Properties of the Italian Version of the Dimensional Obsessive-Compulsive Scale (DOCS) Across Non-Clinical and Clinical Samples

The Dimensional Obsessive-Compulsive Scale (DOCS) is a self-report instrument that assesses the severity of the four most empirically supported OC symptom dimensions (Contamination, Responsibility, Unacceptable Thoughts, and Symmetry). The aim of this study was to investigate the psychometric properties of the Italian version of the DOCS and address associations with socio-demographical variables, psychometric properties in a community (i.e., non-student) sample, and congruence of factor solutions across non-clinical and patient samples. Factor structure, internal consistency, construct, and criterion validity were investigated in three samples of participants (315 from the general population, 106 OCD patients and 31 with other anxiety disorders [OADs]). Results supported the four-factor structure of the DOCS both in clinical and non-clinical sample, and adequate levels of factor congruence across the two samples were found. DOCS scores showed good internal consistency, temporal stability and construct validity, and could adequately discriminate between non-clinical participants, OCD and OADs patients. All the other variables kept constant, associations of DOCS total score with educational level, of Contamination with gender, and of Unacceptable Thoughts with age were also found. These findings suggest that the Italian version of the DOCS retains the adequate psychometric properties of the original, and can be confidently used as an assessment tool of OC symptoms in clinical and research settings.