Validation of the short version of the obsessive compulsive spectrum questionnaire

Aim: In the recent years, a rising amount of research has stressed the importance of a dimensional perspective on mental disorders. In particular, the conceptualization of an obsessive–compulsive spectrum appears to be in line with the very first descriptions of Obsessive–Compulsive Disorder and has been partially acknowledged by the inclusion of the “OCD-spectrum related syndromes and disorders” section in the DSM-5. The goal of the current study is to ascertain the psychometric characteristics of the Obsessive–Compulsive Spectrum–Short Version (OBS-SV), a novel questionnaire designed to measure the complete range of obsessive–compulsive symptoms, from severe full blown to subthreshold ones. Methods: Forty three subjects with a clinical diagnosis of OCD according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5); 42 subjects with a clinical diagnosis of social anxiety disorder (SAD), and 60 individuals without current or lifetime mental disorders (HC) were recruited from the Psychiatric Clinic of the University of Pisa. Subjects were assessed with the SCID-5, the Yale Brown Obsessive Compulsive Scale (Y-BOCS) and the OBS-SV. Results: OBS-SV showed strong test–retest reliability for both the total and the domains scores, as well as a high level of internal consistency. The Pearson’s coefficients for the OBS-SV domain scores ranged from 0.771 to 0.943, and they were positively and strongly linked with one another (p < 0.001). The OBS-SV total score had a strong correlation with each of the OBS-SV domain scores. All correlation coefficients between OBS-SV and additional measures of OCS were observed to be strong, significant and positive. Both OBS-SV domain and overall score differences between diagnostic groups were found to be statistically significant. From HCs, to the SAD, up to the OC group, which had the highest values, the OBS-SV total score grew dramatically and progressively. Conclusion: The OBS-SV demonstrated significant convergent validity with other dimensional OCD measures, excellent internal consistency, and test–retest reliability. Across the three diagnostic categories, the questionnaire functioned differently, with a rising score gradient from healthy controls through SAD patients to OCD subjects.