One-quarter of bipolar I disorder patients experience cycling episodes

Interesting research summary from Psychiatry Matters. It might be time to revise the bipolar section of the DSM in the new 5th Edition (due out in 2013 now).

One-quarter of bipolar I disorder patients experience cycling episodes

14/12/2009

Researchers have found that cycling episodes constitute a quarter of all episodes in bipolar I disorder, suggesting that such a classification should be added to current diagnostic criteria.

MedWire News: Researchers have found that cycling episodes constitute a quarter of all episodes in bipolar I disorder, suggesting that such a classification should be added to current diagnostic criteria.

Currently, alternating syndromes with no intervening period of recovery are classified as separate mood episodes that may wrongly be treated independently.

“This issue is important because it has a direct impact on diagnosis, treatment, and prognosis,” David Solomon (Rhode Island Hospital, Providence, USA) and colleagues explain.

Using data from the ongoing US National Institute of Mental Health Collaborative Program on the Psychobiology of Depression, the team identified 219 individuals diagnosed with bipolar I disorder who had been followed-up for a mean of 17.3 years.

The researchers identified a total of 1208 recurrent mood episodes, with a mean of 5.5 episodes observed per participant. Episodes consisting of a single pole of psychopathology comprised 75% of all mood episodes.

Classification of mood episodes showed that major depression (30.9%) occurred most commonly, followed by mania (20.4%), cycling (17.3%), minor depression (13.0%), hypomania (10.4%), cycling plus mixed state (7.8%), and mixed episodes (0.2%). Overall, cycling episodes constituted 25.1% of all episodes.

Further analysis showed that in the 153 cycling episodes that began with depression, the depressive state was followed by an immediate switch to mood elevation or a mixed state in 64% of cases.

In the 143 cycling episodes that began with mood elevation, the elevated state was followed by an immediate switch to depression or a mixed state in 56%.

When the team examined somatic therapy received during the 1208 mood episodes, they found that 85% were treated with a mood stabilizer and/or an antidepressant for at least 1 week during prospective follow-up.

Furthermore, 40% major depressive episodes, 39% of minor depressive episodes, 12% of manic episodes, and 24% of hypomanic episodes were not treated with a mood stabilizer. In total, 28% of 471 depressive episodes were treated with an antidepressant in the absence of a mood stabilizer.

Writing in the British Journal of Psychiatry, the researchers conclude: “Work groups revising the International Classification of Diseases-10 and the Diagnostic and Statistical Manual of Mental Disorders-IV should add a category for bipolar I cycling episode.”

Reference:
Br J Psychiatry 2009; 195: 525–530

Tags: Psychology, brain, bipolar, Psychiatry Matters, bipolar I, cycling episodes, mania, mixed episodes