Researchers reveal a link between episodic OCD and bipolar disorder

Researchers examining the clinical features of obsessive-compulsive disorder (OCD) have found evidence supporting the existence of an episodic subtype of OCD that is associated with the coexistence of bipolar disorder.OCD is often thought of as being episodic or chronic, and the differences between the two have been investigated in numerous studies. In the current study, Tukel et al. investigated whether episodic OCD should be considered a distinct subtype of OCD. They compared the frequency and clinical features of episodic OCD with that of chronic OCD.A total of 128 outpatients with a primary DSM-IV diagnosis of OCD were included into the study. The researchers compared the patients with episodic OCD (n = 24) and chronic OCD (n = 104) according to their sociodemographic and clinical characteristics. Episodic OCD was defined as a full remission of obsessive-compulsive symptoms that occurs not as a result of pharmacotherapy with serotonin reuptake inhibitors or cognitive behavioural therapy (CBT) and last for at least 6 months.The results revealed the severity of compulsions to be significantly lower in the episodic OCD group compared with the chronic group (p = 0.001). No significant difference was observed in depression and anxiety scores between the two groups; however, a trend towards a higher rate of dysthimia was observed in the chronic group (p = 0.07). Interestingly, a significantly higher comorbidity rate of bipolar disorder (bipolar I and II) was found to occur among patients with episodic OCD than those with chronic OCD (p = 0.01).In discussing their findings the authors pointed out that the lack of a formal definition of "episodic OCD" may be considered a limitation of their study in so far as whether it would be appropriate to categorise patients who are partially remitted, or those whose symptoms are significantly improved but still continue, within the episodic group.This notwithstanding, they note that their findings support the results of previous studies that present evidence of a possible relationship between episodic OCD and bipolar disorder."Although OCD is generally thought to be a chronic disorder with persistent symptoms, increasing evidence shows that a subtype of OCD characterised by an episodic course may exist," the authors concluded.Reference...