This is a pilot study to evaluate the safety and efficacy of deep brain stimulation (DBS) of the nucleus accumbens (NAc) as adjunctive treatment for treatment-refractory opioid use disorder. This study will include 3 individuals with opioid use disorder and relapsing opioid use despite active participation in a drug addiction treatment program.

Three (N = 3) subjects with treatment refractory opioid use disorder will receive bilateral DBS implants in the NAc using the Abbott Medical Infinity DBS system. The primary outcome of this study is to demonstrate the safety of bilateral NAc DBS in patients with treatment-refractory opioid use disorder. Secondary outcomes include time to relapse, remission of opioid use, and change in opioid craving scores. Other secondary outcomes will include the following: Hamilton Depression Scale (HDS), neurophysiological tests, body weight and biochemical markers of health and nutrition. If effective, DBS may reduce opioid use and opioid relapse in people with opioid use disorder who may continue to display relapse despite ongoing multidisciplinary standard of care. DBS brain electrode implantation and implantation of the IPGs and extension wires will be done in the operating room and will require the subject to be admitted post-operatively for an overnight stay. Two weeks after the DBS operation, subjects will undergo systematic testing each of the quadripolar contacts and formal programming. Subsequent parameter settings will be changed at routine outpatient visits based on clinical effects. Standard of care can consist of methadone or buprenorphine maintenance treatment provided by an addiction specialist.

Inclusion criteria

1. Male and females age ≥ 22 years with diagnosis of opioid use disorder (OUD) based on Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5) with at least a 5-year history
2. OUD must be the primary disorder
3. History of ongoing or previous opioid use, relapse, and/or cravings, despite attempts at, or attendance in, at least two different treatment modalities. These modalities may include: Comprehensive Opioid Addiction Treatment (COAT), intensive outpatient COAT, residential treatment, inpatient treatment, alternative to intensive outpatient programs, Drug Dependence Unit programs, medication-assisted treatment (MAT), medication assisted recovery (MAR), inpatient or outpatient rehabilitation, detox programs, Narcotics Anonymous, individual or group therapy, Partial Hospitalization Programs (PHP), Sober living homes, or similar interventions.
4. Self-reports ongoing opioid cravings.
5. Has completed a neuro-psychological evaluation to the satisfaction of a neuropsychologist
6. Has completed a psychiatric evaluation to the satisfaction of a psychiatrist
7. Has had a brain MRI performed and reviewed by neurosurgeon with no contraindication for DBS procedure identified
8. Platelet count > 125,000 per cubic mm and prothrombin time (PT) and partial thromboplastin time (PTT) within normal limits
9. Negative blood cultures to rule out bacteremia

Exclusion criteria

1. Prior brain surgery

2. Baseline assessment on the Hamilton Depression Rating Scale (HAMD) of greater than 17 or moderate risk of suicide based upon a score of 3 or greater on the Columbia Suicide Severity Scale, unless clinical judgment indicates that the individual is appropriate for inclusion despite these scores.

3. History of uncontrolled or persistent seizures

4. Suspected dementia based on neuropsychological screening or Mini Mental State Exam (MMSE) Score < 25

5. Contraindications for MRI:

   1. Presence of implanted electrical stimulation device or other implanted metal devices (excluding dental braces).
   2. Claustrophobia
   3. Body weight exceeding limit of the machine (180 kg/400 lb)

6. Females who are pregnant or nursing. Female subjects of child-bearing potential must have a negative pregnancy test during the pre-op phase and must agree to utilize adequate birth control throughout the trial and for at least 30 days following trial completion.

7. Coagulopathy secondary to chronic need for anticoagulation medicine (e.g. warfarin) or anti-platelet medication (e.g. aspirin or clopidogrel)

8. Diagnosis of neurological disorders (e.g. multiple sclerosis, Parkinson's disease, and stroke)

9. Severe brain atrophy or presence of subdural hygromas or subdural hematomas on brain MRI

10. Any evidence of underlying endocarditis.

11. Primary language other than English

12. Have any other medical condition that, in the opinion of the Investigator, makes the subject unsuitable for enrollment.