Ultimately, it's all in your head

Short White Coat is a blog about learning to be a doctor. Posts appear here as part of White Coat Notes. Ishani Ganguli is a third-year Harvard medical student. E-mail her at shortwhitecoat@gmail.com.

During my recent transition from psychiatry to neurology rotations, I wondered how these two very different specialties would approach the same organ.

In a continuing nod to Descartes, psychiatry traditionally inhabits the realm of the mental, and neurology the physical, subsuming so-called "organic" brain diseases such as stroke and Alzheimer's. Neurologists use darting eyes and knee jerks to puzzle out the location of brain insults, then check their answers against the now almost requisite MRI or CT scan.

In psychiatry, diagnosis requires nuanced conversation with patients. But it is ultimately reduced to an exercise in clustering symptoms using the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), a cookbook-style compendium that’s useful as a standardization tool but recognized by many in the field as flawed.

The line between the two fields was etched somewhat arbitrarily by history and fixed by their cultures. But it’s blurring as brain imaging and molecular biology help solidify our understanding of once intangible diseases of the mind. In fact, the fifth iteration of the DSM, which researchers are now crafting for a planned 2012 release, aims to reclassify diseases based on their genetic underpinnings, response to drugs, and associations with other conditions.

What I hadn’t expected to find, on the flipside, was how much neurology still concedes to the impenetrable mind.

As neurologist-for-a-month, I have learned that a so-called psychogenic diagnosis is usually one of exclusion -- say, leg weakness with no discernable "physical" cause -- and by extension, one of defeat. Maneuvers we use to decipher so-called real versus exaggerated weakness feel patronizing and uncomfortable -- if we cannot believe a patient’s complaints, what becomes of the patient-doctor relationship? -- and I worry that I will become cynical in carrying them out.

Then there’s the "pseudoseizure," for which the name says it all. This phenomenon is defined as a seemingly real seizure with an absence of findings on electroencephalography (in which electrodes are pasted to the scalp to measure the brain’s electrical activity). Interestingly, a research-validated tip-off to doctors is the "teddy bear sign" -- notice a stuffed animal in the hospital room of an adult complaining of seizures, and you’re halfway to this psych diagnosis.

Seeing psychiatry through a neurological lens, it becomes clear that our discomfort with "it’s all in your head" explanations, and the stigma that psychiatric disease cannot seem to shake, is rooted in its intangibility. Without an anatomic or physiological cause to point a finger at, the complaint becomes part of the complainer’s identity.

Will growing insights into psychiatric disease mechanisms change this unfortunate truth?
With time, and with the next DSM, let’s hope so. But perhaps the more important lesson after these two months is that an intangible cause of illness should not invalidate the patient’s experience of it. After all, there’s little we’re certain about in medicine.

And for the record, both neurologists and psychiatrists treat what’s in the head (the brain).