The association between obsessive compulsive disorder and obsessive compulsive personality disorder: prevalence and clinical presentation.

OBJECTIVES: The relationship between Obsessive Compulsive Disorder (OCD) and Obsessive Compulsive Personality Disorder (OCPD) has been the subject of interest for some time due to the historical assumption that OCPD causes OCD. This study systematically examined the association between OCD and OCPD in terms of prevalence and clinical presentation. The specificity of the association between OCD and OCPD was investigated relative to another axis I anxiety disorder (Panic disorder). DESIGN AND
METHOD: Data for this study were drawn from measures taken at initial assessment at a specialist treatment centre for anxiety disorders. Of the 359 participants included in this study, 189 had a principal diagnosis of OCD, while 170 had a principal diagnosis of Panic disorder. Measures included SCID I and II interview modules and self-report measures of anxiety, depression, and OCD syptomatology.
RESULTS: Significantly elevated rates of OCPD were found in OCD relative to Panic disorder. Regardless of axis I disorder, individuals with comorbid OCPD reported more severe depression relative to those without. Participants with both OCD and OCPD had greater self-reported OCD symptom severity, doubting, ordering, and hoarding symptoms at assessment relative to those without OCPD. Participants with OCD and comorbid OCPD also reported significantly higher levels of alcohol consumption.
CONCLUSIONS: There appears to be a significant and specific association between OCD and OCPD. Co-occurring OCD and OCPD is associated with greater severity of impairment in terms of certain OCD symptoms. CLINICAL IMPLICATIONS: The significant and specific association between OCD and OCPD suggests that OCPD occurs more frequently with OCD than previously suggested. A comorbid OCPD diagnosis is associated with a greater degree of depression, regardless of axis I disorder, either OCD or Panic disorder. This is an important consideration, as depression can interfere with therapeutic progress (Foa, 1979). Participants with OCD and OCPD had greater self-reported OCD severity, along with doubting, ordering, and hoarding symptoms, relative to those without OCPD. In clinical practice, where OCD symptoms are severe, and the primary OCD symptoms include doubting, ordering, and hoarding, this may indicate a need to assess for comorbid OCPD. This may be useful in terms of including relevant information in formulation with the patient, and in addressing these issues in treatment. LIMITATIONS OF THE STUDY: There may have been a sampling issue, as the study compared patients from a specialist clinic for the treatment of OCD and Panic disorder. Furthermore, OCD referrals were primary, secondary, or tertiary, whereas Panic disorder referrals were primary or secondary from the immediate catchment area only. This suggests the possibility of greater severity of the OCD sample relative to Panic disorder patients. All participants who met criteria for OCD were assessed for OCPD regardless of whether or not this was indicated by the SCID II screener self-report measure, while participants with Panic disorder were interviewed for OCPD only if indicated by the SCID-II screener. Had participants with Panic disorder been assessed for OCPD regardless of whether or not this was indicated by the SCID-II screener, there is a possibility that a higher rate of OCPD in the Panic disorder sample may have been found.