This is a 8-week randomized, placebo-controlled trial testing the effects of N-acetylcysteine (NAC), on a platform of weekly evidence-based brief alcohol intervention for 120 adolescents with alcohol use disorder (AUD). The primary efficacy endpoint is reduction in alcohol use (total standard drinks), compared between NAC and placebo groups.

Adolescence is a critical developmental stage involving marked elevation in alcohol initiation, progression to AUD, and development of significant, lasting adverse outcomes from use. Effective treatments must be developed for AUD in this especially vulnerable age range. The identification of a well-tolerated, effective pharmacological treatment would represent a significant advance and could yield tremendous public health impact. The proposed trial will provide critical data to evaluate NAC as a highly promising pharmacotherapy for adolescent AUD, and regardless of NAC versus placebo outcomes will provide key methodological guidance for future randomized controlled trials of pharmacotherapies for adolescent AUD. Randomized participants will be provided and instructed to take their assigned medication at 1200 mg twice daily, in approximately twelve-hour intervals.

Inclusion Criteria:

1. Subject is 13-25
2. Must be able to understand the study and provide written informed consent (for participants under 18 years old, a parent/legal guardian must be able to provide consent and the participant must be able to provide assent).
3. Current moderate to heavy drinker by established adolescent criteria
4. Meet criteria for alcohol use disorder
5. Females must agree to use appropriate birth control methods during study participation: oral contraceptives, contraceptive patch, barrier (diaphragm or condom), levonorgestrel implant, medroxyprogesterone acetate, complete abstinence from sexual intercourse, or hormonal contraceptive vaginal ring

Exclusion Criteria:

1. Score >10 on the Clinical Institute Withdrawal Assessment for Alcohol
2. Allergy or intolerance to N-acetylcysteine
3. Females who are pregnant, contemplating pregnancy or lactating over the next 6 months
4. Current use of N-acetylcysteine or any supplement containing N-acetylcysteine (must agree not to take any such supplement throughout study participation)
5. Current enrollment in treatment for alcohol use disorder or expectation of other treatment during protocol participation
6. Any other medical or psychiatric condition or other significant concern that in the Investigator's opinion would impact participant safety or compliance with study instructions, or potentially cofound the interpretation of findings

Randomized participants

6 months (from randomization to final post-treatment follow-up visit)

Adverse events were assessed and documented by the study medical clinician and entered using MedDRA terminology.

Double-blind placebo-controlled pharmacotherapy trial