The comorbidity of Cluster C Personality Disorders in Obsessive Compulsive Disorder as a marker of anxiety and depression severity

Introduction Comorbid Cluster C Personality Disorders (PDs) are the most prevalent PDs in Obsessive-Compulsive Disorder (OCD). Investigating clinical correlates associated to OCD with Cluster C PDs may allow identifying tailored treatment strategies. Objectives The current study examined whether OCD with comorbid cluster C PDs is associated to more severe OCD symptoms, anxiety and depression relative to OCD with comorbid cluster B PDs or OCD alone. Methods Two hundred thirty-nine patients with OCD were included (mean age = 35.64, SD = 11.08, 51% females). Seventeen percent had a comorbid Cluster C PD, 8% had a comorbid Cluster B PD, and 75% had OCD alone. The Structured Clinical Interview for Axis II Disorders, Yale-Brown Obsessive Compulsive Scale, Beck Anxiety Inventory, Beck Depression Inventory-II were administered. Results Patients with comorbid Cluster C PDs reported more severe depression and anxiety than those with comorbid Cluster B PDs (F = 10.48, P < 0.001) or with OCD alone (F = 9.10, P < 0.001). Patients with comorbid Cluster C PDs had more severe OCD symptoms than those with OCD alone but not than those with comorbid Cluster B PDs (F = 3.12, P < 0.05). Conclusions OCD with Cluster C PDs could be a subtype with more severe anxiety and depression. These findings could be explained with the fact that Cluster C PDs are characterized by behaviours, which can be seen as maladaptive attempts to cope with anxiety and depression. Tailored treatment strategies for OCD with comorbid Cluster C PDs are discussed to target co-occurring anxiety and depression.