Everyone knows that alcohol, cigarettes, and illegal drugs are harmful, especially in high amounts, but for people living with addiction, moderation is easier said than done.
Even with regular therapy and medication to help control urges and treat the symptoms of withdrawal, between 50‒70% of people who recover from addiction relapse into their old habits.
Addiction is a real and dangerous illness, and finding a way to treat it effectively could save thousands of lives. So what else can be done that hasn’t been done already? If only we could reach into a patient’s brain and rewire the neural pathways causing them to relapse.
Well, that fantastical wish isn’t far from reality! Modern neurosurgery can alter how neural pathways work by electrically stimulating the brain, and a promising new study shows it might work as a treatment for addiction.
How Addiction Changes Your Neural Pathways
Why hasn’t addiction been “solved” yet, and why do so many people in recovery relapse?
In response to our environment and experiences, our brains form and reinforce neural pathways that govern the way we think and behave. Addiction is no exception.
When a person uses an addictive substance, a “pleasure” neurotransmitter called dopamine floods a neural pathway called the mesolimbic dopaminergic system. The flood of dopamine eventually stimulates the nucleus accumbens (NAc), a part of the brain involved in processing positive stimuli and reinforcing habits.
Unfortunately, if the person continues using drugs, the brain adjusts, or molds, to this new “normal.” A tolerance develops, less dopamine reaches the NAc, and the person has to use more of the drug to feel the same effect. What’s more, as the mesolimbic system changes, less dopamine reaches the NAc, even when the person is sober.
The NAc reinforces habits and survival-related instincts, such as the urge to eat and drink. In order to replace the lost dopamine the NAc should be getting, the individual will feel a visceral urge to use the drug. Getting high is secondary; now they need the drug just to feel normal.
Another major member of the mesolimbic system is the prefrontal cortex, responsible for rational thinking and impulse control. Over time, the neural pathways in the prefrontal cortex of a person with addiction stop working thanks to the neuroplastic changes linked to addiction. As a result, it gets harder and harder to control their urges.
This is, of course, a gross oversimplification of how addiction works. Other forms of physical and mental dependencies, systemic societal issues, and other neural pathways and neurotransmitters contribute as well.
The changes in neural pathways explain how a person can go back to using drugs after turning their life around and being “clean” for months or years. The neural pathways formed and reinforced during the period of drug use are still there, and so is the damage to pathways associated with impulse control.
A Promising New Treatment Emerges
We know the last section was heavy, outlining how addiction can derail a person’s life and health, but this information was necessary to properly explain the conclusions from a recent review providing hope to millions of people struggling with addiction around the world.
This exciting review comes from Dr. Tony Wang and his team of researchers at the University of Virginia. Wang and his team conducted a review of current human and animal studies that show how brain stimulation might be used to treat addiction, and the results are very promising.
What is Deep Brain Stimulation?
Deep brain stimulation is the practice of electrically stimulating neural pathways or structures using implanted electrodes, in order to alter their function. This can be used to restore function to an impaired structure, or to block an unwanted pathway.
This may sound scary, but the procedure is simple, and surprisingly non-invasive! Deep brain stimulation involves a small piece of wire inserted through a small hole in the skull. That’s it!
The electrode is connected to an internal pulse generator (IPG), which is safely implanted in the chest. The IPG delivers small electrical impulses at a safe level, and the whole setup is customized to target the offending brain structures with precision. Once the patient recovers from surgery, deep brain stimulation is effectively painless.
Wang et al. remark how this procedure has been successfully used to treat a range of other neurological and psychological issues—even restoring function to Parkinson’s disease patients who suffer from tremors!
How Can Brain Stimulation Treat Addiction?
Wang and his team suspected that brain stimulation could be used to treat addiction and set out to determine how much evidence there was to back up their hypothesis. They discovered that while a lot more research needs to be done, deep brain stimulation for addiction shows a lot of potential!
According to Wang et al., a wide range of structures in the mesolimbic system and other neural pathways show promise as potential targets for treatment of addiction. These include the prefrontal cortex, with the goal of restoring impulse control, and the separately-wired shell and core of the NAc.
Neuroscientists currently hypothesize that the shell of the NAc is responsible for a person “desiring” their drug of choice, while the core of the NAc causes them to act on that desire. The goal with deep brain stimulation is to interrupt this process.
The animal studies Wang and his team reviewed showed a significant reduction in the drug-seeking behavior of treatment groups almost across the board. For example:
- Morphine-addicted rats were conditioned to go to a specific location in their cages if they wanted the drug. The rats received deep brain stimulation to the ventral striatum over the course of 2 to 9 days. Researchers discovered low-frequency pulses most effectively reduced the rats’ drug-seeking behavior over the course of the study.
- Cocaine-addicted rats were given access to a lever that would intravenously inject the drug to their system. This study found that stimulating the shell of the NAc reduced drug-seeking behaviors, while stimulating the core had little effect.
Sounds Great… What’s the Catch?
Wang et al. point out a few issues with the studies they reviewed. For one thing, human data on this topic is promising but inconclusive. Much more research on humans is needed before deep brain stimulation for addiction is declared safe and effective for the public.
Secondly, there were side effects noted in some animal trials, including unintentional tissue damage, spasms, or infections. On the plus side, these were very rare, and the majority of the studies reviewed reported no adverse effects.
Finally, Wang et al. reiterate several times that the trials on humans and animals they were able to review were generally conducted during the period of drug use. There’s a lot of hope that brain stimulation could be given during the withdrawal period and afterward to prevent relapses, but more evidence is needed to support this.
Wait—Hasn’t This Been Tried Before?
If you were around in the ’70s, these experiments might sound familiar. That’s because methods a little like this have been attempted to treat addiction in the past. Wang and colleagues, however, explain why such methods were abandoned, and help to show how far we’ve come.
In the ’60s and ’70s, neurosurgery was the hottest topic among doctors looking to treat addiction and other psychiatric disorders. Back then, procedures generally involved lesioning—disrupting neural pathways or structures by physically damaging them in hopes of blocking unwanted signals, like the urge to use drugs.
Sadly, this didn’t really work out. These surgeries delivered mixed results, and you can probably imagine how many things could go wrong! Once effective medication became available for neurological and psychological issues, lesioning rapidly fell out of favor.
As the Wang et al. review explains, deep brain stimulation shows promise as a treatment for addiction that doesn’t require invasive brain surgery, and could potentially reduce the need for medication in the future!
When this exciting new method is finally able to be used in humans suffering from addiction, our knowledge of how brain stimulation can change neural pathways will continue to grow. If we’ve come this far since the ’70s, who knows what we’ll accomplish in another 50 years?
Final Thoughts: What This Study Tells Us About The Brain
While this study brings a lot of hope to people with addiction, it also reveals something amazing about our brains that is relevant to people from all backgrounds.
Remember, deep brain stimulation works because the structures that make up our neural pathways communicate, in part, through electrical signals. Delivering electrical impulses to just the right part of the brain can alter how these pathways work.
The mesolimbic system and other pathways associated with reward processing can powerfully reinforce bad habits, but the review by Wang and his team demonstrates that we can take back control. Imagine if we could do something like this to alter neural pathways that interfere with productivity or reinforce negative self-image!
Of course, implanting an electrode into the brain would be a pretty drastic method of self-improvement for people not coping with serious addiction or other illnesses. But electrical stimulation isn’t the only way that people can take control over their brain wiring. You can also make changes to your neural pathways with some dedicated work.
How? Deep brain stimulation works by artificially introducing electrical impulses to targeted pathways, but in place of this external brain stimulation, you can reinforce positive habits at home by working out your brain like a muscle with Innercise™. These science-backed brain exercises can help you overcome everything from procrastination to negative self-talk.
Want to use science-backed exercises to change your life, but not sure where to start? The Brainathon event will help you explore the most effective ways of making your brain work for you with advice from experts on the cutting-edge of the field!