(PS7-73) Diagnostic Stability of Obsessive-compulsive Personality Disorder Across Six Years

 


Background: Obsessive-compulsive personality disorder (OCPD), defined by a preoccupation with perfectionism, orderliness, and control, is the most commonly occurring personality disorder among individuals with OCD (Bulli et al., 2016). Like other personality disorders, OCPD is definitionally assumed to be stable and enduring; however, research suggests that personality disorders may not be as stable as once thought (Sanislow et al., 2009). Even so, OCPD remains under studied, and extant findings related to its course and stability are mixed (Grilo, Sanislow, et al., 2004; Ullrich & Coid, 2009). Given considerable rates of comorbidity between OCPD and OCD, this study aimed to investigate the stability of OCPD in adults with OCD over six years.

Method: 108 participants with a primary diagnosis of OCD were enrolled in the Brown Longitudinal Obsessive Compulsive Study (BLOCS), a naturalistic prospective study on the course of OCD (Pinto et al., 2006). Using the Structured Clinical Interview for DSM-IV Axis II Personality Disorders, participants were assessed for OCPD over six years at baseline, year 3, and year 6. To investigate the diagnostic stability of OCPD, Cochran’s Q test was conducted to assess whether there was a significant change in the proportion of individuals with OCPD over the three time points. Significant results were followed up with paired McNemar’s tests. Analyses were run among three different groups: the total sample, those with OCPD at baseline, and those without OCPD at baseline.

Results: When all participants were included, the percentage of individuals meeting criteria for OCPD changed from 29.6% at baseline to 24.1% at year 3, and to 26.9% at year 6. These changes were not significant, Cochran’s Q (2)=1.86, p=.39, indicating that OCPD remained stable. Among participants with an OCPD diagnosis at baseline (n=32), OCPD decreased significantly to 71.9% at year 3, and further to 59.4% at year 6, Cochran’s Q (2)=15.65, p< .001. Follow-up paired McNemar’s tests showed that the change was significant from baseline to year 3 (p< .01) and from baseline to year 6 (p< .001), but not from year 3 to year 6 (p=.25). Among participants without OCPD at baseline, 3.9% gained an OCPD diagnosis at year 3, and 13.2% at year 6. This change was significant, Cochran’s Q (2)=13.17, p< .01. Follow-up paired McNemar’s tests showed that the change was significant from baseline to year 6 (p< .01) but not from baseline to year 3 (p=.08) or from year 3 to year 6 (p=.05).

Conclusion: Results showing significant increases and decreases in individuals meeting OCPD diagnostic criteria across six years suggest that OCPD may not remain stable, and that it may be common for individuals with OCD to gain or lose an OCPD diagnosis over time. These findings have implications for the conceptualization of personality disorders as stable, and future research should continue to investigate OCPD both in those with and without OCD.