The purpose of this study is to evaluate the efficacy of the medication N-acetylcysteine (NAC) to help young people with alcohol use disorder. NAC is an over-the-counter supplement and antioxidant that has been approved by the Food and Drug Administration (FDA) in adults and children for other uses, but has not been approved by the FDA for treatment of alcohol use disorder. All participants will receive brief alcohol counseling during the 8 weeks of medication treatment. Volunteers ages 13-25 are needed for this study.

The purpose of this study is to evaluate the efficacy of the medication N-acetylcysteine (NAC) to help young people quit using marijuana. NAC is an over-the-counter supplement and antioxidant that has been approved by the Food and Drug Administration (FDA) in adults and children for other uses, but has not been approved by the FDA for treatment of marijuana use disorder. Volunteers ages 14-21 are needed for this study.