Bipolar and nonbipolar obsessive-compulsive disorder: a clinical exploration

Comorbidity of obsessive-compulsive disorder (OCD) in bipolar disorder is well documented. However, clinical characteristics of bipolar OCD are not well studied. The objective of the present study was to compare the clinical characteristics of bipolar and nonbipolar OCD. We chose 28 subjects with bipolar-OCD comorbidity from a sample of 80 remitted bipolar subjects (bipolar OCD) attending the outpatient services of the National Institute of Mental Health and Neurosciences, Bangalore, India, over a period of 11 months. We also recruited 78 nonbipolar OCD subjects consecutively during the same period from the OCD clinic of the institute. They underwent systematic assessment using both structured and unstructured clinical interviews and corroborative information obtained from the immediate family members and the hospital clinical charts. Bipolar OCD subjects were characterized by episodic course of OCD, high family loading for mood disorders, and comorbidity with depression, social phobia, and generalized anxiety disorder. They had less severe OCD and had somewhat different symptom profile compared with nonbipolar OCD. The OCD predated bipolar disorder in 54% of the bipolar OCD subjects; and in the remaining subjects, it had an onset during the course of bipolar disorder. Most bipolar OCD subjects reported worsening of OCD in depression (n = 22, 78%) and improvement in manic/hypomanic episodes (n = 18, 64%). Our findings suggest that OCD in those with a primary diagnosis of bipolar disorder is perhaps pathophysiologically related to bipolar disorder than to OCD. This is strongly supported by the episodic course of OCD, high familial loading for mood disorders, and worsening of OCD in depression with improvement in hypomania/mania phases. There is a need for systematic exploration of the OCD-bipolar comorbidity in both OCD and bipolar samples. Family-genetic and other neurobiological research and the prospective follow-up of bipolar and nonbipolar OCD subjects would further enhance our understanding of this complex comorbidity. The cross-sectional nature of the study based on retrospective assessment of course, the small sample size and the inclusion of only remitted bipolar subjects are the limitations of this study.