Por fin me encontré el articulo del porque la N-acetilcisteina en enfermedades compulsivas...

Trichotillomania: N-Acetylcysteine Shows Promise

This readily available glutamate modulator provided significant improvement in 56% of patients with alopecia caused by compulsive hair pulling.

Trichotillomania is a greatly underrecognized, poorly understood disorder characterized by alopecia caused by hair pulling. Selective serotonin reuptake inhibitors, clomipramine, and behavioral modification have been used but with mixed success.

Glutamatergic dysfunction has been implicated in the pathogenesis of obsessive-compulsive disorder, a disease with a suggested neurobiological link to trichotillomania. N-acetylcysteine (NAC) is an amino acid that modulates the glutamatergic pathway by increasing extracellular glutamate in the nucleus accumbens. NAC has been previously shown to decrease compulsive gambling and cocaine addiction.

Investigators performed a double-blind, placebo-controlled study of NAC treatment for trichotillomania. Fifty patients, aged 18 to 65, with a primary diagnosis of trichotillomania were randomized to receive 1200 mg NAC or placebo every day for 6 weeks. At week 6, if trichotillomania persisted, the dose was increased to 2400 mg/day or a matching increase in placebo pills; 88% of the placebo group and 72% of the treatment group received the dose increase. Patients were evaluated every 3 weeks for 12 weeks; 88% of both groups completed the study.

Patients receiving NAC had significantly greater reductions in hair-pulling symptoms as measured by the Massachusetts General Hospital Hair Pulling Scale (P<0.001) and the Psychiatric Institute Trichotillomania Scale (P=0.001). Fifty-six percent of treatment recipients were "much" or "very much" improved at study completion, compared with 16% of those taking placebo. Significant improvement was observed by 9 weeks of treatment. Although NAC has been known to cause headache, pruritus, flatulence, increased blood pressure, and fatigue, no adverse effects were noted in this study.

Regarding the 44% of treated patients whose symptoms did not improve, the authors hypothesize that trichotillomania represents a heterogeneous disease with different subtypes, some of which may respond better to glutamatergic agents, or may require higher dosages, than others.

Comment: Although long-term follow-up is lacking, the data are promising. The 56% rate of response is similar to rates achieved with other methods. The treatment is inexpensive, readily available in health food stores, and appears to be well tolerated. Further study is warranted to validate safety and efficacy and to determine optimum dosing schedules. A pediatric trial is now under way. Research may lead to a better understanding of the pathophysiology of impulsive-compulsive neurocircuitry and discover better treatments for this distressing condition.

— Mary Wu Chang, MD

Published in Journal Watch Dermatology November 13, 2009

Citation(s):

Grant JE et al. N-acetylcysteine, a glutamate modulator, in the treatment of trichotillomania: A double-blind, placebo-controlled study. Arch Gen Psychiatry 2009 Jul; 66:756.