The amino acid N-acetylcysteine appears to reduce symptoms of compulsive hair-pulling in patients with trichotillomania, according to a report in the July issue of Archives of General Psychiatry, one of the JAMA/Archives journals.

Trichotillomania has been described for almost 200 years and researched for more than two decades, but there is currently no approved treatment for the condition, according to background information in the article. "Trichotillomania is characterized by the following diagnostic criteria: the recurrent pulling out of one's hair, which results in noticeable hair loss; an increasing sense of tension immediately before pulling out the hair or when attempting to resist the behavior; and pleasure, gratification or relief when pulling out hair," the authors write. "Psychosocial problems are common in individuals with trichotillomania and include significantly reduced quality of life, reduced work productivity and impaired social functioning."

The amino acid N-acetylcysteine has previously shown promise in the treatment of repetitive or compulsive disorders and acts on the glutamate system, the largest neurotransmitter system in the human brain, the authors note. Jon E. Grant, J.D., M.D., M.P.H., and colleagues at the University of Minnesota School of Medicine, Minneapolis, conducted a 12-week, double-blind controlled trial of the medication among 50 individuals with trichotillomania (45 women and five men, average age 34.3 years). Twenty-five were randomly assigned to receive 1,200 milligrams to 2,400 milligrams of N-acetylcysteine per day for 12 weeks; the other 25 received placebo.

After 12 weeks, patients taking the active medication had significantly greater reductions in hair-pulling symptoms than those taking placebo. "Fifty-six percent of patients 'much or very much improved' with N-acetylcysteine use compared with 16 percent taking placebo," the authors write. "Significant improvement was initially noted after nine weeks of treatment." None of the participants reported adverse effects.

The magnitude of improvement observed in patients taking N-acetylcysteine was higher than that seen with other medications and similar to that reported for cognitive behavior therapy alone or combined with medication, suggesting that N-acetylcysteine compares favorably with existing treatment options, the authors note. Its efficacy lends further support to the hypothesis that therapies manipulating the glutamate system (called glutamatergic agents) may target core symptoms of compulsive behaviors.

"N-acetylcysteine is an amino acid, is available in health-food stores, is cheaper than most insurance co-payments and seems to be well-tolerated. N-acetylcysteine could be an effective treatment option for people with trichotillomania," the authors write. Future studies should evaluate long-term effects of the treatment as well as its efficacy when combined with behavioral therapy, they conclude. "As effective treatments for hair pulling emerge, it becomes increasingly important that physicians and mental health care providers screen for trichotillomania to provide timely treatment."

Dr. Grant has received research grants from the National Institute of Mental Health, Forest Pharmaceuticals, GlaxoSmithKline and Somaxon Pharmaceuticals; has been a consultant to Pfizer Pharmaceuticals and Somaxon Pharmaceuticals; and has consulted for law offices as an expert regarding impulse control disorders.