Obsessive-compulsive personality disorder co-occurring with obsessive-compulsive disorder: Conceptual and clinical implications

Objectives: There are ongoing uncertainties in the relationship between obsessive-compulsive disorder (OCD) and obsessive-compulsive personality disorder (OCPD). This study aimed to test the proposition that OCPD may be a marker of severity of OCD by comparing groups of OCD individuals with and without OCPD on a number of variables. Method: A total of 148 adults with a principal diagnosis of OCD were administered the Mini International Neuropsychiatric Interview, Yale-Brown Obsessive-Compulsive Scale, Sheehan Disability Scale, Vancouver Obsessional Compulsive Inventory and Symptom Checklist 90-Revised. Participants with a DSM-IV diagnosis of OCPD were compared with those without OCPD. Results: Some 70 (47.3%) participants were diagnosed with OCPD. The groups of participants with and without OCPD did not differ significantly with respect to any of the demographic variables, clinician-rated severity of OCD, levels of disability and mean age of onset of OCD. All self-rated OCD symptom dimensions except for contamination and checking were significantly more prominent in participants with OCPD, as were all self-rated dimensions of psychopathology. Participants with OCPD had significantly more frequent hoarding compulsions and obsessions involving a need to collect and keep objects. Of Axis I disorders, only panic disorder was significantly more frequent in participants with OCPD than in those without OCPD. Conclusions: A high frequency of OCPD among individuals with OCD suggests a strong, although not necessarily a unique, relationship between the two conditions. This finding may also be a consequence of the blurring of the boundary between OCD and OCPD by postulating that hoarding and hoarding-like behaviours characterise both disorders. Results of this study do not support the notion that OCD with OCPD is a marker of clinician-rated severity of OCD. However, individuals with OCPD had more prominent OCD symptoms, they were more distressed and exhibited various other psychopathological phenomena more intensely, which is likely to complicate their treatment.