Glutamate is to blame

"As psychiatric symptoms go, hair-pulling is among the earliest recorded. According to Dr. Jon Grant, a trichotillomania expert at the University of Minnesota School of Medicine and the lead author of the new paper, Hippocrates himself said that in order to test whether patients were faking their illness, doctors must ask whether they are pulling out their hair. The behavior is so commonly associated with distress that the stock phrase to describe a stressful situation is that it causes you to tear your hair out.

We seem wired to attack our hair under traumatic conditions, possibly because forcibly extracting hair is painful; it can divert attention from stress to the more immediate matter of how to solve a pressing problem. For chronic hair pullers, that diversion turns into addictive psychological relief. Some people with trichotillomania pull out hairs not only from their heads but also from their pubic areas and armpits; as many as 20% eat their hair; a small minority pull other people's hairs. "Many say it's not painful but more of a sense of just a tug, one that provides a calming feeling," says Grant. "Some of these people are not even aware they are pulling their hair. Their spouses will say, 'Stop that,' and they are not even aware they have a clump of hair on their lap."

Grant theorizes that trichotillomania may be a kind of grooming irregularity that falls into the obsessive-compulsive family of disorders. "Some parrots pull out all their feathers," he says. "Some mice pull out all their fur."

That may explain why the antioxidant N-acetylcysteine can help prevent it. The compound is thought to work by reducing the synaptic release of a neurotransmitter called glutamate. As Grant told me, glutamate is the communication chemical that "tells the brain, 'Do it! Do it! Do it! Do it!' And the rest of the brain can be overwhelmed by this drive state." Reduce glutamate and you may reduce the drive state. Previous studies have suggested the supplement may also reduce urges to use cocaine and to gamble."


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