The relationship between obsessive-compulsive disorder (OCD) and obsessive-compulsive personality disorder (OCPD) has not yet been fully clarified. The aim of the present study was to analyze DSM-IV OCPD prevalence rates in OCD and panic disorder (PD) patients to test for the specificity of the OCPD-OCD link, and to compare them to OCPD prevalence in a control group of subjects without any psychiatric disorder. A total of 109 patients with a principal diagnosis of DSM-IV (SCID-I) OCD and 82 with PD were interviewed using the Structured Clinical Interview for DSM-IV Axis II Disorders (SCID-II) in order to assess the prevalence of OCPD. All patients with a coexisting axis I diagnosis were excluded from the study to eliminate confounding factors when evaluating the association between prevalence rates of OCPD and anxiety disorder diagnoses. An exclusion criteria was also a Hamilton Depression Rating Scale (HAM-D) score >/=16. A sample of comparison subjects (age 18 to 65 years) without any psychiatric disorder was recruited from people registered with two general practitioners (GPs), whether or not they consulted the doctor, in order to evaluate OCPD prevalence rate in the community. A significant difference was found between the prevalence of OCPD in OCD (22.9%) and in PD (17.1%) on one hand, and that in the comparison sample (3.0%) on the other. No differences were found between the two psychiatric groups, even when splitting the samples according to gender. Our study failed to support the hypothesis of a specific relationship between OCPD and OCD; we confirmed the higher prevalence rate of this personality disorder in OCD subjects with regard to the general population, but we also confirmed the higher rate of OCPD in another anxiety disorder which is phenomenologically well characterized and different from OCD, such as PD.
