Comorbidity in obsessive–compulsive disorder (OCD): A report from the International College of Obsessive–Compulsive Spectrum Disorders (ICOCS)

BACKGROUND: Obsessive-compulsive disorder (OCD) is often associated with significant psychiatric comorbidity. Comorbid disorders include mood and anxiety disorders as well as obsessive-compulsive spectrum disorders (OCSDs). This paper aims to investigate comorbidity of DSM Axis I-disorders, including OCSDs, in patients with OCD from 10 centers affiliated with the International College of Obsessive-Compulsive Spectrum Disorders (ICOCS). METHODS: This is a cross-sectional study of comorbidity of Axis I disorders including OCSDs in 457 outpatients with primary OCD (37% male; 63% female), with ages ranging from 12 to 88years (mean: 39.8±13). Treating clinicians assessed Axis I disorders using the Mini International Neuropsychiatric Interview and assessed OCSDs using the Structured Clinical Interview for OCD related/spectrum disorders (SCID-OCSD). RESULTS: In terms of the OCSDs, highest comorbidity rates were found for tic disorder (12.5%), BDD (8.71%) and self-injurious behavior (7.43%). In terms of the other Axis I-disorders, major depressive disorder (MDD; 15%), social anxiety disorder (SAD; 14%), generalized anxiety disorder (GAD; 13%) and dysthymic disorder (13%) were most prevalent. DISCUSSION: High comorbidity of some OCSDs in OCD supports the formal recognition of these conditions in a separate chapter of the nosology. Rates of other Axis I disorders are high in both the general population and in OCSDs, indicating that these may often also need to be the focus of intervention in OCD.