Research Report: An Addiction Remission Brain Circuit

doctors holding images of brain
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By Christopher Johnston, MD ABPM-ADM, Chief Medical Officer, Pinnacle Treatment Centers

The Search for New Evidence-Based Treatments for Addiction

Doctors, therapists, counselors, and research scientists learn more about addiction every day. At the moment, there’s widespread consensus on the most effective way to treat addiction. The treatment community agrees that the integrated treatment model yields the best results. This approach to treating substance use disorder (SUD) or alcohol use disorder (AUD) includes:

  • Individual therapy/counseling
  • Group therapy/counseling
  • Family therapy/counseling
  • Treatment of any co-occurring mental health disorders:
    • A person with an SUD/AUD who also has a mental health disorder receives a diagnosis for a co-occurring disorder
  • Medication, as needed:
    • People with opioid use disorder (OUD) may participate in medication-assisted treatment, when appropriate, with the following medications:
      • Buprenorphine
      • Methadone
      • Naltrexone
    • 12 step groups:
      • Narcotics Anonymous (NA)
      • Alcoholics Anonymous (AA)
    • Lifestyle changes:
      • Health eating
      • Exercise
      • Stress management techniques
    • Aftercare plans, which include:
      • Relapse prevention
      • Contingency management
      • Community support resources
    • Practical support:
      • Vocational assistance/connection to vocational resources
      • Housing assistance/connection to housing resources
      • Education assistance/connection to educational resources

We know this approach to treatment can help people achieve long-term, sustainable recovery. But we also know that relapse happens, and that every day, new people develop alcohol and substance use disorders. We know people who relapse don’t want to, and in most cases, people who develop an addiction don’t want to, either.

That’s why scientists keep working to improve our understanding of the neurobiological mechanisms of addiction. They want to improve the lives of the individuals affected by addiction. Their research may lead to treatments that reduce chance of relapse, and possibly reduce the chance of developing an alcohol or substance use disorder in the first place. That’s why a recent study caught our attention, which we’ll discuss in a moment.

Addiction and the Brain: What do We Know?

Neuroscientists know a great deal about the neurobiology of addiction. However, the knowledge we gain from their research helps treatment professionals address the behavioral characteristics of people with addiction, which over time, lead to changes – or restore maladapted patterns – in the underlying neurobiological mechanisms of addiction neuroscientists learn about through research.

What we don’t have, to date, is the ability to target specific aspects of brain function with medication or other therapies that reduce rates of relapse or prevent the development of addiction disorders. We have medication-assisted treatment (MAT), which does leverage our knowledge of neurobiology and neuropharmacology, but that’s a different subject altogether.

To learn more about MAT, click here.

What we’re talking about now is using our knowledge of how the brain works to treat the brain itself in order to treat addictive behaviors. I discuss what we know about addiction and the brain in this article The Neurobiology of Addiction – Emotion, Impulse, and Decision-Making. Here’s a quick summary of what I talk about in that piece. As of now, we know the following brain areas play a role in addiction:

Frontal/prefrontal Cortex

The frontal and prefrontal cortex areas are the executive function areas of the brain. They aid in predicting outcomes of actions, managing impulses, regulating reactions to emotion – among other things.

The Amygdala

The amygdala is the core of the reward system of the brain. It plays a role in how we seek and experience pleasure, as well as contributing to how the brain generates and regulates motivation, emotions, and behavior. It’s brain region that has a special function: it receives signals brain areas associated with emotion and transmits information to areas directly related to behavior.

The Insula

The insula is involved in our survival needs. It communicates information to the amygdala and the frontal/prefrontal cortex about our subjective, immediate state, including our experience of pain, pleasure, and reward.

Here’s where the new article we mention above comes in: the research moves past our knowledge of different brain areas and addiction and identifies brain circuits – i.e. specific patterns of neuron firing/neurological activity – that play a role in addiction. In this study, researchers used a technique called lesion networking to identify three brain circuits associate with addiction remission: two related to nicotine remission, and one related to alcohol remission.

How Brain Mapping Helps Us Learn About Addiction

In order to create maps of brain function, researchers need data – and lots of it.

In order to learn how the brain works, one thing researchers do is pay close attention to what happens when someone has an injury or an event, such as a stoke, that causes brain lesions, a.k.a. brain damage. When a person has a stroke and researchers can identify exactly what area of the brain was damaged, and connect that area to a specific behavior, such as smoking or not smoking – i.e. remission or addiction – they then record their findings with pictures of the brain obtained through magnetic resonance imaging (MRI). Over the years, researchers have amassed enough data on the areas of the brain to identify the function of specific brain areas and brain circuits. All of this data is available to colleagues through a database called The Human Connectome Project.

In the study that got our attention, called Brain Lesions Disrupting Addiction Map to A Common Human Brain Circuit, researchers analyzed the records of two groups of patients who were addicted to smoking cigarettes at the time they experienced brain lesions due to a stroke. After recovery, twenty-six percent of the patients met criteria for remission of nicotine addiction, which means they:

  • Quit smoking easily
  • Did not start smoking again
  • Did not crave cigarettes or nicotine

Next, researchers examined the brain lesions of the people who achieved remission. The records were puzzling at first, because the MRI data showed lesions in different brain areas in different patients. However, when they compared these brain lesions to brain maps created by the connectome project, they realized that all the lesions in the people who achieved remission from smoking were connected to two unique brain circuits.

What This Meant for Brain Research

That was an important finding, because it allowed them to create what they label an addiction remission network. That’s something new in the neurobiology of addiction. We know about brain circuits and networks, even those networks associated with addiction. The amygdala is part of the limbic system, for instance, which is related to reward, which is related to addiction. No research has ever shown that lesions in the amygdala or limbic system affect addiction, however, in the way the lesions in this study affected remission of nicotine addiction.

Here are the details.

Brain Lesions and Addiction Remission

  • A lesion positively connected to the insula (see above) and the cingulate gyrus (part of the limbic system) but negatively connected to the prefrontal cortex would “likely lead to addiction remission.”
  • A lesion positively connected to the prefrontal cortex but negatively connected to the insula and cingulate gyrus would be “the least likely to lead to addiction remission.”
  • The connectivity pattern was stable across:
    • Age of patients
    • Amount of smoking before lesion
    • Size of lesion
  • The connectivity pattern was stable across patients’ functional level of:
    • Verbal comprehension
    • Intelligence, as measured by intelligence quotient (IQ)
    • Executive function
    • Working memory

That’s not all. To test the generalizability of their results, the research team compared these connectivity patterns to brain maps in the connectome database from patients who had experienced lesions that led to remission of alcohol use disorder – and found the connectivity patterns were so similar that they could be called a match. That last sentence is heavily qualified because when comparing brain function across a large database like the connectome project, there’s a great deal of variation across individual data points (brains) even within a well-established brain network. In other words, the way one brain fires when doing a task may be slightly different than the way another brain fires, although the task is identical and the network involved is the same.

That’s a long way of saying the nicotine remission map was the same as an alcohol use disorder remission map.

And that’s a big deal.

How We Can Use This to Treat Addiction

That’s the next step.

Currently, there’s a technique called transcranial magnetic stimulation (TMS) that’s approved by the Food and Drug Administration (FDA) for use for depression treatment, and has recently been approved for smoking cessation therapy. In TMS, clinicians place a magnetic coil against a patients forehead and delivers a pulse that influences a previously identified and targeted brain area.

The researchers in the study identified brain voxels – 3-D areas created by MRI images – that directly coincide with the brain areas connected to remission circuits. They theorize that positive nodes in the remission maps are ideal places to place a focal lesion that disrupts addiction, while negative nodes in the remission maps are ideal places for brain stimulation using TMS.

You read that correctly: they propose that if future research can prove an absence of negative side effects, intentional lesions in the correct places on the remission maps they created could lead to remission of addiction for nicotine, alcohol, and other substances. At the same time, they propose stimulation of the negative nodes – which are the inverse of the positive nodes on the remission maps – could also lead to remission of addiction for nicotine, alcohol, and other substances.

The confounding factor here is the complexity of the human brain itself. Lesion and stimulation of brain areas may cause “subtle behavioral changes across multiple different domains” that researchers have yet to identify. However, initial data on their proposed lesion/stimulation sites is encouraging. To date, trials with stimulation for smoking cessation have not shown adverse side effects.

That’s where we are now: the clinical trial phase.

In the words of the study authors:

“Whether noninvasive brain stimulation, such as TMS, can provide a lasting change to [addictive] behavior is to be determined.”

When the data arrive, we’ll share what we learn. This research effort may lead to a radical change in the way we treat addiction. If it does, we’ll rejoice – and that’s not an exaggeration. However, it may simply give us another evidence-based technique that takes its place alongside therapy, counseling, MAT, and lifestyle changes that characterize our current best-known approach to addiction treatment, the integrated treatment model. That’s good, too. We’ll use all the data-driven, evidence-based techniques at our disposal to help people overcome addiction and achieve lifelong, sustainable recovery.

The materials provided on the Pinnacle Blog are for information and educational purposes only. No behavioral health or any other professional services are provided through the Blog and the information obtained through the Blog is not a substitute for consultation with a qualified health professional. If you are in need of medical or behavioral health treatment, please contact a qualified health professional directly, and if you are in need of emergency help, please go to your nearest emergency room or dial 911.