The goal of the project is to improve the care of Veterans with mild traumatic brain injury (mTBI) and unhealthy alcohol use.

This is a pilot controlled clinical trial that aims to assess the efficacy of N-acetylcysteine (NAC) to reduce alcohol use and improve brain injury symptoms in Veterans with mTBI who consume alcohol at hazardous or harmful levels.

Inclusion Criteria:

1. Male and female veterans
2. Ages 18-65 (inclusive)
3. A history of mTBI as defined by American Congress of Rehabilitation Medicine (ACRM), in the chronic, stable phase of recovery (>6 months from injury).
4. Current (past month [30 days]) Hazardous or Harmful Alcohol Use: Hazardous use is drinking that meets NIAAA criteria: Current (past 30 day) weekly drinking, consisting of an average of 15 standard drinks/week for men or 8 standard drinks/week for women. Harmful use is drinking behavior that meets DSM-5 criteria mild AUD.
5. Participants must express a desire to reduce or stop alcohol use.
6. Female subjects that must have a negative urine pregnancy test and must be either postmenopausal one year or practicing an effective birth control method.

Exclusion Criteria:

1. Unstable psychotic or bipolar disorders, dementia, or other psychiatric disorders judged to be unstable in the clinical judgment of the PI or study physician.
2. Clinically significant unstable medical conditions, in the clinical judgment of the PI or study physician.
3. Female patients who are pregnant or nursing.
4. Concurrent participation in another alcohol treatment study, or in any research study involving medications.
5. Requiring acute medical detoxification from alcohol based on a score of 12 or more on the Clinical Institute Withdrawal Assessment of Alcohol Scale (CIWA-AD).
6. NAC use in the past week prior to study entry.
7. Use of AUD treatment medications (disulfiram, naltrexone, or acamprosate) within the past week.
8. Participants who are legally mandated to participate in an alcohol treatment program.
9. Participants who have had a suicide attempt in the past 3 months or suicidal ideation, with intent, in the 30 days prior to enrollment.
10. Participants who in the opinion of the investigator should not be enrolled in the study because of the precautions, warnings or contraindications outlined in the NAC package insert.
11. Participants with known hypersensitivity to acetylcysteine

Over 12 weeks.

We used the Adverse Event Symptom Checklist at every study visit (Visits 0 - 8 and 12), which assessed the most reported adverse events listed in the FDA Prescribing Information.