Findings from a randomized clinical trial indicated efficacy and tolerability of N-acetylcysteine, an amino acid shown to restore extracellular glutamate concentration in the nucleus accumbens, for skin-picking disorder.
“Although apparently fairly common (estimated prevalence rate, 1.4% to 5.4%), [skin-picking disorder] remains poorly understood, with limited data regarding underlying pathophysiology and treatment. There is currently no medication treatment for [skin-picking disorder] approved by the [FDA].” Jon E. Grant, JD, MD, MPH, of the Pritzker School of Medicine, University of Chicago, and colleagues wrote. “In fact, to our knowledge, there have been only four small placebo-controlled trials published on the treatment of [skin-picking disorder].”
To assess efficacy of N-acetylcysteine for compulsive skin-picking behavior, researchers randomly assigned individuals with skin-picking disorder to N-acetylcysteine (n = 35) or placebo (n = 31) for 12 weeks. Dosing ranged from 1,200 mg to 3,000 mg per day. Study participants had a mean age of 34.8 years. Skin-picking severity was determined via modified Yale-Brown Obsessive Compulsive Scale (NE-YBOCS) and the Clinical Global Impression-Severity Scale. Cognitive flexibility was also assessed.
From baseline to 12 weeks, NE-YBOCS scores improved from 18.9 to 11.5 among participants who received N-acetylcysteine treatment, compared with 17.9 to 14.1 among those who received placebo (P = .048).
Clinical Global Impression-Severity scale scores improved from 3.5 to 3 among the N-acetylcysteine group, and did not improve among the placebo group (4 to 4.2; P = .003).
These effects were significant in terms of treatment by time interactions and post-hoc analysis at one or more individual time points, according to researchers.
At study completion, 47% of the N-acetylcysteine group was “much or very much improved,” compared with 19% of the placebo group (P = .03).
Psychosocial functioning did not significantly differ between treatment groups, according to researchers.
“This investigation suggests that N-acetylcysteine appears to be effective and well tolerated in the acute treatment of [skin-picking disorder]. As effective treatments for skin picking emerge, it becomes increasingly important that physicians and other mental health care professionals screen for the disorder to provide timely treatment,” the researchers concluded. – by Amanda Oldt
Grant reports receiving research grants from the National Institute of Mental Health (NIMH U01MH076179), National Center for Responsible Gaming, and Forest and Roche Pharmaceuticals; yearly compensation from Springer Publishing for acting as editor-in-chief of the Journal of Gambling Studies; and royalties from Oxford University Press, American Psychiatric Publishing Inc, Norton Press and McGraw Hill. Please see the full study for a list of all authors’ relevant financial disclosures.