NAC Reduces Marijuana Dependence

CHARLESTON, S.C.N-acetylcysteine (NAC), an amino acid supplement often used for its antioxidant benefits, helped adolescents with marijuana dependency stay abstinent in  the first randomized controlled trial of pharmacotherapy for cannabis dependence to show a positive cessation outcome (Am J Psychiatry 2012; DOI: 10.1176/appi.ajp.2012.12010055). Adolescents aged 15 to 21 years were more than twice as likely to remain abstinent when they received NAC versus placebo in addition to counseling, researchers said.

In an eight-week trial, about 44 percent of adolescents assigned to take 1,200 mg of NAC twice daily had negative urine test results for cannabinoids at the end of treatment, compared with 32 percent of those taking placebo. Four weeks after the end of treatment, only 19 percent of the NAC group and 10 percent of those assigned to placebo still had negative urine test results. However, the analysis was conducted on an intent-to-treat basis, with a positive test result automatically assigned to participants not showing up for testing.

In the eight-week double-blind randomized placebo-controlled trial, treatment-seeking cannabis-dependent adolescents (N=116) received NAC (1,200 mg) or placebo twice daily as well as a contingency management intervention and brief (less than 10 minutes) weekly cessation counseling..

Dropout rates in the study were substantial, with 60 percent of the original 116 participants retained through the treatment period and just under half providing samples at the four-week follow up. However, there were no significant differences in retention between the NAC and placebo groups.

NAC has previously shown to protect against muscle injury.