This is a phase I, non-blinded, non-randomized, pilot trial for safety and efficacy of DBS for AUD. Patients who meet inclusion and exclusion criteria will be identified and recruited from the practices of Sunnybrook psychiatrists. Five (5) to ten (10) subjects will be enrolled and study duration for each patient will be of one (1) year. Our primary objective is to establish the safety of DBS in a patient population with treatment refractory AUD. In addition to demonstrating safety, our second primary objective will be to evaluate if DBS-targeted nucleus accumbens in alcoholism is efficacious in the treatment-refractory patients with AUD. This will be measured by various outcome measures that will include validated scales to assess addiction and craving behaviours.

Inclusion criteria

1. Female or Male patients between age 18-70
2. Diagnosis of alcohol use disorder (AUD) as defined by the Diagnostic and Statistical Manual fifth edition (DSM-5).
3. History of AUD for at least 2 years, with evidence of repeated failure to respond to evidence-based AUD treatments (psychosocial treatments plus pharmacotherapies such as disulfiram, naltrexone and acamprosate).
4. Alcohol Use Disorders Identification Test (AUDIT) Scale Score >8
5. Ability to provide informed consent and comply with all testing, follow-ups and study appointments and protocols

Exclusion criteria

1. Any past or current evidence of psychosis or mania
2. Current suicidal or homicidal ideation
3. Active neurologic disease, such as epilepsy
4. Visible brain damage or atrophy in CT or MRI scan
5. Any contraindication to MRI or positron emission tomography (PET) scanning
6. Likely to relocate or move during the study's one year duration
7. Presence of clinical and/or neurological conditions that may significantly increase the risk of the surgical procedure.
8. Patients with renal dysfunction (GFR<60)
9. Pregnant or lactating