Is the Comorbidity of Obsessive-compulsive Disorder with Bipolar I Disorder Less than Major Depressive Disorder?

Based on current evidence, comorbidity of obsessive-compulsive disorder (OCD) in bipolar patients is higher than in patients with major depressive disorder (MDD). However, there is little data regarding the comparison of this comorbidity between bipolar I disorder (BID) and MDD. The aim of the present project was to carry out this comparison. 466 patients referred to four psychiatric university centers in Tehran were evaluated by DSM-IV diagnostic criteria checklist. The rates of lifetime comorbidity of OCD in MDD and BID patients were calculated, and data were analyzed by descriptive and analytic statistical methods. 124 cases of MDD and 115 cases of BID were diagnosed. The demographic variables of two groups did not have significant difference. The rate of admissions and recurrent type of disorder in the BID group were significantly higher than those of the other group. The lifetime comorbidity of OCD in MDD and BID patients was 17.7% and 7%, respectively, and the difference was statistically significant (p<0.05). There was no case of comorbidity of OCD in patients with first episode of mania. The rates of comorbidity of OCD in patients with single episode MDD and with recurrent MDD did not have significant difference. The lifetime comorbidity of OCD in patients with MDD is significant and may be higher than in BID patients.