N-acetylcysteine (NAC) for Children With Tourette Syndrome

Summary

Tourette syndrome is a childhood-onset neuropsychiatric disorder characterized by multiple motor and vocal tics that last for at least a year in duration. Currently, there exist several effective pharmacological treatments for childhood tics including alpha-2 agonist medications (guanfacine and clonidine) and neuroleptics (antipsychotic) medications. These medications, however, have significant side-effects and are only partially efficacy in treating tics. N-acetylcysteine (NAC) is a natural supplement that acts as an antioxidant and glutamate modulating agent. NAC has been used safely for decades in doses 20-40 times higher than in this trial as an antidote for acetaminophen overdose. The only side-effect commonly seen with NAC is nausea and this side-effect is seldom seen in the doses used in this trial. NAC has recently been demonstrated to be effective in a double-blind, placebo-controlled trial in adults with trichotillomania (chronic hair pulling). Hairpulling is hypothesized to be closely related to tics because these conditions (1) have similar clinical characteristics -- both groups typically experience urges before engaging in pulling or tics, (2) neuroimaging studies suggest they involve similar brain circuits -- the basal ganglia, (3) the same pharmacological treatments (neuroleptics) may be effective for both conditions and (4) they tend to be inherited together in families. In other trials NAC has evidence of some efficacy in treating diverse psychiatric conditions such as bipolar depression, schizophrenia and cocaine dependence. The investigators are conducting this trial to determine if NAC is an effective treatment for tics.

Timeline

Start

2010-07

Primary completion

2014-01

Completion

2014-01

Publications

• Background Grant JE, Odlaug BL, Kim SW. N-acetylcysteine, a glutamate modulator, in the treatment of trichotillomania: a double-blind, placebo-controlled study. Arch Gen Psychiatry. 2009 Jul;66(7):756-63. doi: 10.1001/archgenpsychiatry.2009.60.
• Background Bloch MH, Leckman JF. Clinical course of Tourette syndrome. J Psychosom Res. 2009 Dec;67(6):497-501. doi: 10.1016/j.jpsychores.2009.09.002.
• Background Berk M, Copolov DL, Dean O, Lu K, Jeavons S, Schapkaitz I, Anderson-Hunt M, Bush AI. N-acetyl cysteine for depressive symptoms in bipolar disorder--a double-blind randomized placebo-controlled trial. Biol Psychiatry. 2008 Sep 15;64(6):468-75. doi: 10.1016/j.biopsych.2008.04.022. Epub 2008 Jun 5.
• Background Berk M, Copolov D, Dean O, Lu K, Jeavons S, Schapkaitz I, Anderson-Hunt M, Judd F, Katz F, Katz P, Ording-Jespersen S, Little J, Conus P, Cuenod M, Do KQ, Bush AI. N-acetyl cysteine as a glutathione precursor for schizophrenia--a double-blind, randomized, placebo-controlled trial. Biol Psychiatry. 2008 Sep 1;64(5):361-8. doi: 10.1016/j.biopsych.2008.03.004. Epub 2008 Apr 23.
• Background Ng F, Berk M, Dean O, Bush AI. Oxidative stress in psychiatric disorders: evidence base and therapeutic implications. Int J Neuropsychopharmacol. 2008 Sep;11(6):851-76. doi: 10.1017/S1461145707008401. Epub 2008 Jan 21.
• Background Singer HS, Morris C, Grados M. Glutamatergic modulatory therapy for Tourette syndrome. Med Hypotheses. 2010 May;74(5):862-7. doi: 10.1016/j.mehy.2009.11.028. Epub 2009 Dec 21.
• Results Bloch MH, Panza KE, Yaffa A, Alvarenga PG, Jakubovski E, Mulqueen JM, Landeros-Weisenberger A, Leckman JF. N-Acetylcysteine in the Treatment of Pediatric Tourette Syndrome: Randomized, Double-Blind, Placebo-Controlled Add-On Trial. J Child Adolesc Psychopharmacol. 2016 May;26(4):327-34. doi: 10.1089/cap.2015.0109. Epub 2016 Mar 30.

Drugs

Indications