So Much For Bipolar Disorder Being Underdiagnosed
I imagine two or three of you remember a study that came out last year asserting that bipolar disorder was being overdiagnosed–or wrongly diagnosed–in almost 50 percent of patients. The study was authored by Mark Zimmerman, a psychiatry professor at Brown University, and colleagues and was quite controversial, although some researchers supported his findings. After all, bipolar disorder is supposed to be underdiagnosed and most of the leading lights in psychiatry consider bipolar to be a fixed diagnosis. Once you’re diagnosed with it, there is no escape. Shut up and take your meds or you’re living in denial and will die and so on. I wrote a lengthy rant about Zimmerman’s findings last year.
I spoke with Zimmerman last year and asked him if such a large chunk of patients didn’t have bipolar disorder then what did they have. He didn’t want to speculate as he was working on a follow-up paper that would lay out what some of the bipolar overdiagnosees might actually have. My own hunch was that a large proportion of the people would wind up with major depression.
Zimmerman’s follow-up paper came out a couple of weeks ago, ahead of print, in the Journal of Clinical Psychiatry. It looked at 82 former bipolars and found:
“Results: The most frequent lifetime diagnosis in the 82 patients previously diagnosed with bipolar disorder was major depressive disorder (82.9%, n = 68). The patients overdiagnosed with bipolar disorder were significantly more likely to be diagnosed with borderline personality disorder compared to patients who were not diagnosed with bipolar disorder (24.4% vs 6.1%; P < .001). A previous diagnosis of bipolar disorder was also associated with significantly higher lifetime rates of major depressive disorder (P < .01), posttraumatic stress disorder (P < .05), impulse control disorders (P < .05), and eating disorders (P < .05), although only the association with impulse control disorders remained significant after controlling for the presence of borderline personality disorder."
So there you have it: lots of depression and a bit of borderline personality disorder. The depression certainly makes sense. I’m not as clear on the BPD and will await a copy of the entire paper before trying to make sense of it. Of course, the new study is based on 82 patients–which doesn’t exactly give you population-wide predictability–so it would be nice if some other researchers tried to replicate its findings.
Obviously, Zimmerman’s findings do have implications for millions of Americans, psychiatry, Big Pharma and all kinds of alleged advocacy groups, but that’s for another day.
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Posted in Furious Seasons