Naltrexone in AUD Reward Drinkers

Inclusion Criteria: * Age 18-65 years old * Willing to provide signed, informed consent and commit to completing the study procedures * Able to read at an 8th grade or higher level * Current DSM-5 diagnosis of AUD * Reports consuming 24+ standard drinks (men) or 18+ standard drinks (women) weekly on average over the month prior to consent * Expresses a desire to reduce or stop drinking and a willingness to receive two injections of study medication over 8 weeks of treatment. * Either a reward drinker \[i.e., an individual with a score of 19 or greater on the reward subscale and less than or equal to 18 on the relief subscale of the Inventory of Drinking Situations (IDS)\] or a relief drinker (i.e., an individual with a score of 21 or greater on the relief subscale and less than or equal to 18 on the reward subscale of the IDS). * Has a stable address in the local area; not planning to move; has documents for an ID check * Women of child-bearing potential (i.e., who have not had a hysterectomy, bilateral oophorectomy, tubal ligation or are less than two years postmenopausal): must be non-lactating and practicing a reliable method of birth control and have a negative urine pregnancy test prior to the initiation of the study procedures. Examples of medically acceptable methods for this protocol include oral contraceptive pills, intrauterine device, injection of Depo-Provera, Norplant, contraceptive patch, contraceptive ring, double-barrier methods (such as condoms and diaphragm/spermicide), male partner sterilization, abstinence (and agreement to continue abstinence or to use an acceptable method of contraception, as listed above, should sexual activity commence). Exclusion Criteria: * Planned surgery within the timeframe of the study * A current, clinically significant physical disease or abnormality on the basis of medical history, physical examination, or routine laboratory evaluation that could interfere with study participation or make it hazardous for the subject to do so (e.g., bleeding disorder, pancreatitis, epilepsy, diabetes, liver disease, kidney disease, or cardiomyopathy as determined by history and clinical exam); ALAT or ASAT concentration greater than 3 times the upper limit of normal (ULN), or direct bilirubin above the ULN. (Note-abnormal laboratory tests during screening may be repeated once). * Chronic or episodic painful conditions that could require opioid medications for pain control * History of seizure disorder (excluding childhood febrile seizures) * History of allergy or other serious adverse event due to treatment with XR-NTX * Current psychotic disorder (bipolar, schizophrenia, major depression with suicidal ideation, or psychotic features) identified by clinical examination or the structured interview that could interfere with study participation or make it hazardous for the subject. * Current DSM-5 diagnosis of any drug use disorder other than alcohol, nicotine, or cannabis or a urine drug screen that is positive for benzodiazepines, opioids, amphetamines, cocaine or barbiturates. * Current treatment with a psychotropic, anticonvulsant, opioid, anticoagulant or AUD treatment medication (i.e., naltrexone, acamprosate, disulfiram, topiramate, gabapentin, varenicline, or baclofen) * Receipt of any experimental medication within the past 30 days * In need of medical detoxification from alcohol * Subjects cannot have been mandated by court for alcohol or drug abuse treatment or have pending legal proceedings that could result in incarceration within 6 months of enrollment. * Homicidal or other behavioral disturbance that requires immediate clinical attention * Judged by the principal investigator or his designee to be an unsuitable candidate for study participation