Patients with bipolar disorder and comorbid obsessive-compulsive disorder (OCD) present with more depressive episodes and are at a greater risk for treatment-emergent mania than their peers with bipolar disorder alone, research shows.

As the comorbid patients also had a greater burden of anxiety and impulse control disorders the findings raise the possibility that this group represents a distinct disease entity.

A recent analysis of the US Epidemiological Catchment Area Study data set found that lifetime rates of OCD in patients with bipolar disorder and major depression were 21% and 12.2%, respectively.

“Although OCD-bipolar disorder comorbidity is now considered highly prevalent, very few controlled studies have examined the impact of comorbid OCD on the course and treatment of bipolar disorder,” Beny Lafer (University of São Paulo School of Medicine, Brazil) and colleagues comment in the journal Acta Neuropsychiatrica.

For the present study the researchers recruited 30 clinically stable female outpatients with bipolar disorder, divided into two groups: bipolar disorder-OCD, consisting of 15 patients; and bipolar disorder only, also 15 patients.

The groups were matched for age, ethnicity, education, and socioeconomic status.

Following structured clinical interview with the DSM-IV, Lafer and team found that the bipolar disorder-OCD patients presented with a greater number of previous depressive episodes, more chronic episodes, and more residual symptoms after an episode, than the bipolar disorder only patients.

Of the bipolar disorder-OCD patients, 86% had a history of treatment-emergent mania, compared with only 40% of the bipolar disorder only patients.

In addition patients with bipolar disorder-OCD showed a higher prevalence of several psychiatric disorders compared with the bipolar disorder only patients, including any anxiety disorder (93.3 vs 53.3%); impulse control disorders (60% vs 13.3%); eating disorders (33.3 vs 0%); and tic disorders (33.3 vs 0%).

“Although the data available are insufficient to allow us to define OCD-bipolar disorder comorbidity as a distinct entity, future research examining the familial-genetic and neurobiological aspects of this comorbidity will further the understanding of its exact nature,” Lafer and colleagues conclude.

MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2010

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A considerable number of older patients with bipolar II disorder or bipolar disorder not otherwise specified (BP-II/BP-NOS) are initially misdiagnosed as having major depressive disorder (MDD), study findings show.

As monotherapy with antidepressants can have adverse effects in elderly patients with bipolar disorder as well as in younger patients, the researchers call for clinicians to keep “the soft forms of bipolar disorder in the differential diagnosis for late-life depression.”

They found that younger age at onset of the first major depressive episode, more frequent prior major depressive episodes, and the existence of depressed mixed state could help clinicians identify elderly bipolar patients.

Minoru Takeshima and Koichi Kurata, from Ishikawa Prefectural Takamatsu Hospital in Kahoku City in Japan, reviewed the medical charts of 87 patients aged at least 60 years who had been hospitalized due to a major depressive episode.

The final diagnoses were MDD in 55 (63.2%) patients and bipolar disorder in 32 (36.8%) patients. Among the bipolar disorder diagnoses, six were for bipolar I disorder, 24 were for BP-II, and two were for BP-NOS.

The researchers note, however, that most of the 26 patients with BP-II/BP-NOS had initially been misdiagnosed. Nineteen (73%) were initially diagnosed with MDD (61.0%) or other disorders (dementia, adjustment disorder; 12.0%).

In contrast, only 9.0% and 34.0% of patients who were finally diagnosed with MDD or bipolar I disorder, respectively, were initially misdiagnosed.

The results, published in the Journal of Affective Disorders, show that patients with BP-II/BP-NOS were significantly younger than patients with MDD at the onset of the first major depressive episode, at a median of 52 versus 66 years.

In addition, patients with BP-II/BP-NOS were significantly more likely to have three or more major depressive episodes than were patients with MDD, at a rate of 40.0% versus just 5.5%.

Depressed mixed state also distinguished patients with BP-II/BP-NOS from those with major depressive disorder, occurring in 61.5% and 16.4% of patients, respectively.

Multiple logistic regression analysis confirmed that younger age at onset of first major depressive episode (odds ratio [OR]=0.94) and depressed mixed state (OR=6.22) were independent markers of bipolarity.

The researchers conclude: “The present study showed that a considerable number of older patients who were hospitalized due to major depressive episode had been initially misdiagnosed with MDD and were actually BP-II/BP-NOS patients, similar to younger bipolar cohorts, in whom such misdiagnosis is a major problem.”

MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2010

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