Could Experimental Brain Surgery Solve the Opioid Epidemic?

Addiction – or substance use disorder (SUD) – is a complex condition that involves uncontrollable, recurrent use of substance despite its harmful consequences to the individual’s health, personal, and professional life. SUDs are one of the most widely spread mental disorders in the US, with around one in thirteen reporting having one in the past year. Due to the nature of the condition, people dealing with a SUD have an increased risk of an overdose due to the increased amount of drug the user takes over time.

One type of drug in the US that is commonly abused are opioids. Some drugs in this category include: morphine, heroin, hydrocodone, oxycodone, and fentanyl. These substances have been prescribed by doctors since the 1990s after surgery or during cancer treatment due to their effective pain-relieving qualities. Opiate rehabilitation in the US is offered in private and government-funded environments, depending on one’s needs and availability.

Alongside their pain treatment benefits, opioids also cause intense feelings of euphoria in its users, making these drugs highly addictive. This quality has triggered a spiraling illicit use of the opiates across the US and created a prolonged epidemic. People usually start abusing either through recreational experimentation or from misusing a prescription, with around 10.1 million people misusing their opioid prescription in 2019.

In 2021, the Centers for Disease Control and Prevention (CDC) recorded over 100,000 drug overdose deaths, an increase of 28.5% compared to 2020. Out of these deaths, around 60% could be attributed to opioid use. The number of national overdose deaths has been increasing since the 90s; however, the pandemic caused these numbers to drastically increase. This can mainly be attributed to the population’s declining mental health.

Opioid Addiction in the Brain

The brain’s reward system is responsible for feelings of pleasure via the release of endorphins and controls behavior through this circuit. When an enjoyable activity is carried out – such as eating tasty food or listening to music – the brain’s reward circuit is “turned on.” This activation causes our brain to reinforce that something important is occurring that is worth remembering and repeating.

Taking drugs also falls into the category of an enjoyable activity and causes the release of neurotransmitters – such as dopamine – in the brain. The euphoric feelings these substances produce hijack the reward system and push people to return to the drug. Over time as users take a substance more, the brain builds tolerance to the drug and causes more intense cravings for larger amounts of the drug.

Looking specifically at opioids, these drugs interact with opioid receptors around the central nervous system. When they bind together, they trigger the release of dopamine, flooding the circuit with feelings of pleasure. Over time, this changes the chemical and physical structure of the brain and causes the user to need a dosage of the drug to function properly and avoid withdrawal symptoms.

People experiencing an opioid use disorder currently undergo a medical detox where the drug is flushed out of their system, followed by a rehabilitation program which includes different kinds of therapies and healthy lifestyle changes. Although this kind of approach works for some people, many are calling for more effective treatments.

The Brain Surgery That Could Tackle Opioid Addiction

West Virginia has an especially high death rate compared to the rest of the US population, inflated to three times as much as the national rate. Between June 2020 and June 2021, overdose death rates in West Virginia increased by almost 32%, again a much higher rate than the US overall at 21%. This region’s numbers are due to a combination of:

  • The population’s worsening mental health
  • Lack of mental health support
  • Lack of substance abuse education
  • Sociocultural factors
  • A depressed economy
  • A high rate of prescribing and dispensing prescription opioids

Doctors in the region at the Rockefeller Neuroscience Institute, have been developing a novel approach to tackle opioid use disorders. Here, volunteers who have a chronic opioid addiction underwent experimental brain surgery to break the powerful reward center circuit cycle. The surgery – termed deep brain stimulation (DBS) – entailed implanting miniscule electrodes in the reward center of the brain (nucleus accumbens) where they will send electrical impulses to hopefully rewire the individual’s pleasure-seeking behaviors. The probes will also stimulate an area where heavy drug taking damages, called the frontal cortex. This area is involved in decision-making and is vital to higher thought.

DBS has already been successful in treating Parkinson’s Disease symptoms and slowing the disease’s progression for decades. It has also been approved by the US Food and Drug Administration to treat a number of other ailments including obsessive-compulsive disorder and severe epilepsy.

“Our hypothesis was that by using the DBS in this part of the brain, we would essentially be normalizing the dopamine levels,” explained Dr Ali Rezai, executive chair of the Rockefeller Neuroscience Institute. The doctors hope these implants will be effective at reducing the intensity of cravings and create an effective treatment method for people who have exhausted other rehabilitation methods. Ultimately, they hope to reduce the number of overdose deaths.

James Fisher was the third individual to take part in the study. Fisher has been addicted to drugs since being a teenager – primarily benzodiazepines – and has suffered four near-fatal drug overdoses. After having the DBS surgery, he reported no longer feeling depressed, anxious, or experiencing any intense drug cravings.

Out of the people who volunteered for the trial, three out of four did not relapse and were able to manage their withdrawal symptoms effectively. One of the participants unfortunately relapsed and had their probe removed. Researchers are now planning a second, larger phase of the clinical trial to more accurately see this therapy’s success rates in a larger sample size.