Sunday, December 12, 2010

Diagnostic Errors and The Shrink

Meg sent me a link to Happiness in The World (what an upbeat name for a medical blog!) and The Danger of Early Closure. She wanted to know how it pertains to psychiatry.
The author writes: Sometimes doctors gather all the clues correctly, think all the right things based on those clues, and still get it wrong. But in this case, another significant thought error contributed to the misdiagnosis: my tendency to come to early closure.

Early closure, it turns out, is a danger that lies in wait mostly for seasoned clinicians (far more commonly, at least, than for medical students and residents). Because seasoned clinicians rely more on pattern recognition to make diagnoses and often come to their conclusions rapidly, they’re at far greater risk for leaping toward those conclusions without examining all other should present (luckily for us all, this is the exception and not the rule). At other times, however, these mistakes are made because the physician was simply in a hurry, or tired, or didn’t care enough to think through the evidence in ways he should have, saw a pattern he thought he recognized, and stopped asking the most important question a physician can ever ask: what else could this be? relevant possibilities. Patients often present with a constellation of symptoms that don’t entirely fit the diagnosis they actually have. Often the discrepancies between these presentations and the textbook descriptions are unimportant—but sometimes those discrepancies exist not because the patient’s body hasn’t read the textbook, but because the diagnosis the doctor makes is the wrong one. Such misdiagnoses are occasionally unavoidable: the symptoms with which the patient presents are simply too far afield from the way the medical literature says the disease

It’s the same with us all. We all come to early closure all the time, forming opinions about the behavior of others without sufficient consideration of all relevant facts. We become attached to the explanations that make the most sense from the perspective of our own experience and our own point of view.

Do we do this in psychiatry? Of course. It's not at all uncommon for a psychiatrist to diagnosis a patient with Major Depression when, in fact, the patient has Bipolar Disorder. Why? Sometimes there has been no episode of mania (yet) and a diagnosis can't be made. Other times the symptoms have been explained away as something else: an exuberant personality, anxiety, a reaction to events. And finally, sometimes the doctor simply forgets to ask about such episodes or the patient/family don't report them as they've drawn their own conclusions.

What else? Psychiatrists may attribute mood instability to personality disorders. This is the case less and less, as we've found that when people's mood stabilizes, so does their behavior. Or a psychiatrist may see a patient who is very distraught after an upsetting life event and attribute the mood changes to an adjustment disorder, when in fact the patient has developed depression. Hopefully, we re-think our diagnosis if the symptoms persist or don't follow the usual course.