July 9, 2007

Eternal Thunderstorms of the PTSD Mind

By: Joanne McNeil

When patients taking the high blood pressure medication propanolol reported a decrease in stage fright, researchers at Harvard Medical School and McGill University began to wonder whether the drug might relieve even bigger anxieties. Tests are currently underway on post-traumatic stress disorder patients. Comparisons to The Eternal Sunshine of the Spotless Mind are inevitable, as the trial consists of a patient first thinking about and writing down every detail of his unwanted memory, just before taking propanolol. This erases the memory. Following that, a patient is said to experience no measurable stress response when he listens to a retelling of the traumatic experience.

“Why should you have to live with it every day of your life? It doesn’t erase the fact that it happened. It doesn’t erase your memory of it. It makes it easier to remember and function,” one of the patients in the study said to Leslie Stahl on 60 Minutes.

There’s a reason why you might be able to recall the worst moment in your life better than your entire afternoon at the office. Trauma activates the amygdala, which in turn releases stress hormones or adrenaline. It acts as a sealant, enhancing the memory formation in the brain. Traumatic memories are first storied in the hippocampus and chemical reactions encode them into neurons in the cerebral cortex (responsible for long term memory.) As a person recalls his incident of trauma, the memory is relayed back to the hippocampus, which often times releases more stress hormones, creating another layer of laminate over that painful memory.

The hippocampus is the area of the brain responsible for learning, which is why every time we think about a memory the less “pure” it becomes. Revisiting a memory is like opening up a Word document and editing it with a perspective gleaned in intervening period. Ironically, the purest memories are held in the brains of amnesiacs, as they are incapable of accessing them. Otherwise, every time we think of a memory, we add something, or take away, or otherwise alter what was an experience lived at a certain time or place.

Anyone who remembers the child molestation witch hunts in the mid-80s, knows how easy it is to “implant” a memory. Yet, deleting memories seems beyond belief. We naturally assume our memories exist undefined by limits and physical space. The entire process seems infinitely complex and intertwined, retrievable only by happenstance, like Proust dipping his madeleines.

The research makes memory deletion seem shockingly easy. The doctors in Eternal Sunshine had their share of difficulty vacuuming Jim Carey’s brain, so the idea its real life counterpart might be available in pill form seems premature and chilling.

The major difference is, doctors are not suggesting propanolol be used to erase ex-girlfriends, or even that one time you wet the bed at summer camp. The reason PTSD sufferers are candidates for this research is their experience and the memory itself stimulates more adrenaline than normal. Consider that the hormone revs up in “fight or flight” situations. In survival mode our sense are all heightened. That accounts for a clearer memory of the event, and sometimes, anxiety and other hormonal panic responses when the memory replays. This physical anxiety is why the propanolol works at all.

Nevertheless, one can’t help but think of sci-fi plots much more dystopic than Charlie Kauffman’s. Aren’t memories what make us individuals?

The President’s Council on Bioethics has condemned the study in a report saying, this drug application, “risks making shameful acts seem less shameful or terrible acts less terrible than they really are,'”and risks “undermining our true identity.” But if one’s true “identity” cages him in with a never-ending nightmare, maybe that’s reason to change.

Joanne McNeil is Brainwash‘s Science and Tech Editor. Her website is joannemcneil.com.