Is comorbid Obsessive-compulsive Personality Disorder responsible for a longer duration of untreated illness in Obsessive-Compulsive Disorder?

Background and aims: Obsessive-Compulsive Personality Disorder (OCPD) is marked by a pervasive preoccupation with orderliness, perfectionism, and control, often overlapping with Obsessive-Compulsive Disorder (OCD) in terms of rigid and repetitive behaviors. While OCD behaviors are ego-dystonic and confined to specific areas of life, OCPD behaviors are ego-syntonic and affect overall functioning. Although the relationship between OCD and OCPD has been object of investigation, the impact of OCPD comorbidity on OCD remains underexplored. This study examines potential clinical differences between OCD patients with and without comorbid OCPD, with a specific focus on duration of untreated illness (DUI). Methods: A sample of 300 patients diagnosed with OCD was consecutively recruited from a OCD Tertiary Clinic. Patients with OCD were divided into two groups: those with OCD-only and those with comorbid OCPD. Sociodemographic and clinical variables were collected and compared between groups. An additional age- and sex-matched sensitivity analysis was performed to further assess the robustness of the main findings. Results: Out of the 300 patients with OCD, 18.6% (n = 56) were also diagnosed with OCPD. The age at first pharmacological treatment was significantly higher in the OCD with OCPD group compared to the OCD-only group (32.16 ± 17.06 years vs. 27.48 ± 11.17 years; p < .05). The DUI was significantly longer in the OCD with OCPD group (9.2 ± 12.4 years vs. 6.10 ± 8.06 years; p < .05). These findings remained significant after controlling for potential confounding by age and sex through a 1:1 matched sensitivity analysis. Conclusion: Almost one out of five patients with OCD has comorbid OCPD. The ego-syntonic nature of OCPD beliefs may contribute to treatment delays, underscoring the importance of early identification of this specific comorbidity in OCD patients to improve treatment outcomes.