There has been a lot of discussion about the over-diagnosis of bipolar disorder in kids, but what about in adults? In the wake of increased bipolar awareness and vigilance, are doctors mistaking other disorders or even excessive irritability and anger as bipolar disorder? If the doctor has a hammer, does everything start to look like a nail?
Researchers in Rhode Island have looked at this specific question and found evidence of a pattern of over-diagnosis of bipolar disorder in adults. In a study published in 2008, Zimmerman and others reported that out of a group of 700 patients who had previously received a diagnosis of bipolar disorder, fewer than half met the criteria when given a more comprehensive psychiatric evaluation.
In 2010, the same researchers published additional data about the 82 people in the study who had been given a prior diagnosis of bipolar but did not meet criteria for the diagnosis under more careful scrutiny. The most common diagnosis in that group was borderline personality disorder. There was a high rate of co-occurrence with higher rates of conditions such as major depression, post traumatic stress disorder (PTSD), impulse control disorders, and eating disorders, but these were often folded into the borderline diagnosis.
The core diagnostic confusion in both adults and children, it seems to me, is due to the brewing notion that mood reactivity or dysregulation, characterized by chronic irritability, anger, and explosive behavior, may be some variation on the more well defined, discrete mood episodes (depression or manic or mixed ) seen in classical bipolar disorder.
Many different types of mental illness can cause chronic irritability and problems with anger. The question seems to be whether more of these illnesses should come under the bipolar label. The label is important because it guides treatment. However, based on the diagnostic criteria that we currently have in the DSM IV, unless a pattern of sustained episodes of hypomania, mania, or mixed states accompanies the depression, then it is not bipolar disorder.
Is there scientific evidence for this idea of a spectrum of mood regulation problems that includes bipolar disorder at one end and irritability and explosive rages at the other? The answer is a resounding “We don’t know.” But until we have more specific data to say otherwise, we rely on the diagnostic structures that are in place. We won’t have more objective answers to these questions until genetic research and studies of actual brain structure and function help us understand the true neurological story of these conditions. These will lead us to more standardized ways to classify and treat bipolar disorder and its potential variations.
In the meantime, we must be as scrupulous and detailed as possible in making these diagnoses and be humble about our abilities to accurately distinguish between chronic irritability with dysregulated mood and the cycles of bipolar disorder. We need to listen to our patients and ourselves as our starting point and not get stuck in an inflexible way of thinking or diagnosing our patients, since we are far from having a truly scientific vision that will guide us in purely objective ways.