Sociodemographic and clinical characteristics of the study sample.

<p>HDRS, Hamilton Depression Rating Scale; OCD, Obsessive-Compulsive Disorder; SD, Standard Deviation; y, years; YBOCS, Yale-Brown Obsessive Compulsive Scale.</p>a<p>Statistic value corresponds to ANOVA’s F or t-student test for continuous variables and chi-square test for categorical variables.</p>b<p>Age at onset was defined as the age when symptoms became a significant source of distress and interfered with the patient’s social functioning.</p>c<p>A positive familial history of OCD was considered when a first or a second order relative had been formally diagnosed by a psychiatrist.