Opioid addiction is a chronic brain disease characterized by compulsive drug seeking and use despite harmful consequences. It is considered a major public health crisis in many parts of the world including the United States, where over 47,000 opioid overdose deaths occurred in 2017 alone. While medications and behavioral therapies can be helpful for some, many individuals with severe, treatment-resistant opioid addiction require more intensive interventions.
Deep brain stimulation (DBS) has recently emerged as a potential therapeutic option for these hard-to-treat cases.
How Does Opioid Addiction Develop?
Repeated use of opioids like heroin, fentanyl, and prescription painkillers leads to long-term changes in the brain’s reward circuitry. The mesocorticolimbic dopamine system, comprising projections from the ventral tegmental area to the nucleus accumbens and prefrontal cortex, is central to drug reward and reinforcement.
Opioids increase dopamine levels in this system, producing euphoria and compelling users to repeat the experience. With sustained use, counter adaptations occur – the reward system becomes dysfunctional, leading to tolerance, withdrawal, and cravings when opioids are discontinued. These powerful neurobiological factors underlie the compulsive drug seeking that is the hallmark of addiction.
Current Treatments and Their Limitations
Medications and behavioral therapies are the mainstays of opioid addiction treatment. Methadone, buprenorphine, and naltrexone act on opioid receptors to reduce cravings and block euphoric effects. While such pharmacotherapies are effective for some, treatment outcomes remain modest – relapse rates exceed 50% within 6 months after detoxification. Psychosocial interventions like cognitive behavioral therapy and contingency management can improve outcomes when combined with medications, but are not sufficient alone for many addicted individuals.
Up to 20% of opioid addicted individuals do not respond adequately to current treatments. These people with severe, refractory addiction continue high-risk opioid use despite all interventions. They require repeated detoxifications and have multiple drug overdoses – some ultimately succumb to an overdose death. Novel therapies beyond the existing paradigm are desperately needed for this treatment-resistant population.
Deep Brain Stimulation for Addiction
Deep brain stimulation (DBS) is an emerging experimental therapy that could fill a major unmet need in addiction treatment. DBS involves surgically implanting electrodes into specific brain regions which are then stimulated with adjustable patterns of electrical pulses. It was originally developed to treat Parkinson’s disease, but is now being investigated for severe, refractory cases of addiction.
DBS directly changes the activity of dysfunctional brain circuits that underlie addictive behaviors. Stimulation of certain regions can reduce drug cravings, prevent relapse, and normalize reward system impairments for some individuals not helped by other options. It may offer a lifeline for those suffering from unrelenting opioid addiction by directly correcting the pathological neurobiology.
Mechanisms of DBS for Addiction Treatment
DBS is believed to exert therapeutic effects in addiction mainly through modulation of the mesocorticolimbic dopamine system. Chronic drug use drives dopamine changes that keep the system in an abnormal state of activation. Effective restoration of dopamine functioning could therefore normalize reward processing and reduce compulsive behavior.
Animal studies indicate DBS may act through several dopamine-mediated mechanisms:
- Increasing tonic dopamine levels while reducing phasic dopamine released during drug-seeking behavior
- Normalizing dopamine receptor signaling, especially D2, which is impaired in addiction
- Altering dopamine neuron firing patterns from rapid, burst firing towards steady tonic activity
- Reversing drug-induced changes in glutamate transmission onto dopamine neurons
- Normalizing functional connections between prefrontal and subcortical reward regions
In essence, DBS seems capable of directly counteracting many of the dopamine deficits underlying the loss of control in addiction. The clinically relevant details of these mechanisms continue to be investigated.
Target Regions for DBS in Addiction
Various brain targets for DBS in addiction treatment have been explored, but two key frontostriatal circuits with dopamine system involvement have emerged:
Nucleus accumbens (NAc)
The NAc is a hub integrating cognitive, emotional, and motor information to regulate motivation. It is central to drug reward processing and a major target of dopamine projections. NAc DBS may reduce drug cravings, extinction learning, and relapse.
Medial forebrain bundle (MFB)
The MFB contains dopamine cell bodies and fibers running between the ventral tegmental area, NAc, and prefrontal cortex. MFB DBS appears to normalize dopamine neurotransmission and drug cue reactivity.
While other targets like the subthalamic nucleus and ventral capsule/ventral striatum exist, the NAc and MFB have the most empirical support so far. Ongoing research continues to optimize DBS parameters and electrodes at these sites.
Clinical Research on DBS for Addiction
Early clinical experience with DBS for addiction treatment has been promising but limited to small trials and case reports. Rigorously controlled trials are still needed.
Some highlights of the emerging human evidence include:
- A 2017 case report on NAc DBS for opioid addiction described how stimulation eliminated cravings and led to abstinence in a patient after multiple failed treatment attempts.
- In a 2018 open-label trial of MFB DBS for opioid use disorder, electrodes were implanted in 6 patients. Cravings decreased, and median time abstinent increased from 0.08 to 0.50 years over 24 months.
- A 2020 case series following 5 patients with severe alcohol use disorder found ventral striatum DBS led to years of sobriety. Cravings and alcohol cue reactivity were also reduced.
- In 2021, a randomized trial of NAc DBS included 10 opioid addicted individuals after detox. The stimulated group had lower cravings and were more likely to avoid relapse during treatment.
This limited data suggests DBS could have clinically meaningful benefits in severe, refractory addiction, but placebo-controlled trials in larger populations are still lacking. Multiple research groups are currently undertaking such trials which will provide stronger evidence.
Ethical Considerations of DBS for Addiction
Addiction is an ethically complex disease. As an invasive neuromodulation therapy, DBS raises additional ethical issues requiring careful thought.
Some considerations include:
- Ensuring truly informed consent from a vulnerable population prone to poor decision making
- Selecting appropriate patients who failed multiple prior treatments and have capacity to consent
- Monitoring stimulation effects on personality, autonomy, and authenticity of patients’ desired behaviors
- Avoiding coercion; DBS should not be mandated by third parties like criminal justice systems
- Preventing unintended worsening of cognitive or psychiatric problems often co-occurring with addiction
- Assessing impact on moral responsibility and free will when behaviors are modulated by a device
- Considering justice issues if access to expensive DBS therapy is inequitable across socioeconomic groups
DBS for addiction has potential for misuse – thorough safeguards are necessary. But this should not preclude cautious, ethical research to help those suffering from severe, untreatable disease. The risk/benefit ratio must be thoughtfully evaluated for each patient.
Substance Abuse Billing
The use of deep brain stimulation to treat severe cases of opioid addiction has potential to greatly help patients who fail standard therapies. However, significant costs are associated with this emerging treatment that present challenges to accessibility and insurance coverage.
The DBS procedure itself incurs expenses for the neurostimulation device, implantation surgery, and post-operative programming. Estimates indicate total first-year costs per patient exceed $35,000. There are also ongoing costs for maintenance, replacement procedures, and battery replacements averaging $17,000 every 3-5 years. These costs often exceed those of traditional addiction treatments covered by insurance.
Gaining insurance coverage for DBS in opioid addiction can be difficult since it remains an off-label use still under investigation. Some plans may deny coverage as experimental or investigational. Advocacy is needed to have DBS for addiction recognized as medical necessity for severe, refractory illness. Creative solutions like value-based pricing and risk sharing with device manufacturers could also help expand access to this life-saving therapy for those in need.
Opioid addiction treatment generates substantial costs that impose a heavy burden on the healthcare system. From detox and rehabilitation programs to medications and counseling, medical expenses add up – as do expenses from complications like infections and overdoses. This has significant implications for medical billing and coding for opioid addiction services.
Specific CPT codes exist to bill for treatment of opioid use disorder. These include diagnosis codes reflecting dependence, abuse, and mental/behavioral disorders, as well as codes for screening, therapy/counseling, and medications like buprenorphine. Proper coding is crucial to maximize reimbursement and avoid unnecessary claim denials from insurers. Complications and comorbidities may require additional diagnostic codes on billing submissions.
Navigating insurance coverage for opioid addiction can be highly complex. Plans may limit coverage of medications or non-pharmacologic treatments. Preauthorization may be required for residential rehab programs costing tens of thousands of dollars. Coordination of benefits across medical, pharmacy, behavioral health is key. Maintaining access and preventing lapses in cash flow is an ongoing struggle for opioid treatment providers reliant on steady reimbursement. Substance abuse billing expertise is essential.
Future Outlook
DBS is unlikely to become a first-line addiction treatment anytime soon. But it holds unique promise for the sizable minority who fail current therapies. With rigorous research, DBS could become part of standard care for these most desperate, refractory cases.
To achieve this, further work is needed on optimal brain targets, stimulus parameters, biomarkers, and patient selection criteria. DBS technology continues advancing too – “closed loop” systems delivering stimulation in response to brain signals may someday refine treatment effects.
While many questions remain, DBS appears capable of directly recalibrating brain circuits awry in addiction. This innovation signifies a potential paradigm shift in therapy – from managing behavioral symptoms to correcting the underlying neuropathology. DBS may thus provide a lifeline for those not helped by existing treatments, paving the way for an era of personalized neurotechnology in addiction medicine.