Obsessive beliefs in first-degree relatives of probands with obsessive-compulsive disorder: is the cognitive vulnerabilità in relatives specific to OCD?

Background: Specific dysfunctional beliefs have been identified as candidate endophenotypes for Obsessive-Compulsive Disorder (OCD). Rector et al. (2009) investigated cognitive vulnerability for OCD and their results support both the notion of familial-based origin of obsessive beliefs, and the hypothesis that inflated responsibility/overestimation of threat, could represent candidate endophenotypes for OCD. Aims: The primary aim of this study was to replicate previous findings of a familial cognitive vulnerability for OCD. The secondary purpose was to test the hypothesis that obsessive beliefs of patients with OCD and those of their first-degree relatives (FDRs) are correlated, supporting dysfunctional beliefs as candidate endophenotypes for OCD. Method: 65 patients with DSM-IV-TR (SCID-I) OCD were included together with one healthy FDR. 77 non-affected FDRs of patients with Bipolar Disorder were enrolled as a control group. Obsessive beliefs were measured with the OBQ-44. Results: First-degree relatives of subjects with OCD scored significantly higher than controls on the total score and on the domain tapping inflated responsibility and overestimation of threat. There was no significant correlation between each obsessive belief in patients with OCD and their non-affected FDRs. Conclusions: Our study provides evidence of a specific cognitive vulnerability for OCD in FDRs of probands with OCD.