Possible Treatments for Remapping the Addicted Brain

Researchers may have found a new way to treat the addicted brain. It involves a brain circuit that we could see targeted as a potential remedy.

We have traditionally had two main routes to addiction treatment and recovery. On the one hand, we have relatively imprecise, blanket medications like SSRIs. On the other, we have behavioural and psychotherapies, which, whilst effective, can produce limited results in the presence of a chronic condition.

However, this new direction of research and the promising results we are already seeing offers something much different. It represents both a leap forwards in our understanding of the addicted brain and a new potential avenue for treatment.

The (addicted) brain

Nobody truly understands the human brain. It is by far the most complex or the body’s many organs. It is arguably also the most important. Everything we do as a species and as individuals runs through the brain – in a very real sense, we are our brains.

In short, our brains regulate our body’s most basic functions whilst enabling us to respond to external stimuli. They shape our behaviours, our senses of selves, our very world itself, both external perceptual and internal. The addicted brain brain is no different.

It is everything you think and feel; it is you. Even Descartes at his most sceptical recognised the existence of his own brain: cogito ergo sum - I think therefore I am.

The brain as a computer

If you want to picture how the brain works, there are worse metaphors than that of a large computer. In fact, there are whole branches of philosophy dedicated to the idea that this is more than just a metaphor. We really are the world’s first processors.

Rather than silicon chips, our brains are made of billions of neurons, or brain cells. These form networks and circuits very similar to those you would find in your MacBook. Each neuron acts like a switch. If you think of Turing’s enigma machine, these are the levers and controls that dictate the flow of information.

A neuron will fire off if it receives enough signals from the other neurons in its circuit or network. It will then send its own signals out, creating something of a community of data spreading neurons.

Our brains are formed from diverse parts with interconnected circuits bringing them all into something of a whole. These different brain circuits all have their own specific functions, and networks of neurons make them work by firing signals back and forth to one another. They send these signals to different parts of the brain, to the spinal cord, and to the peripheral nervous system – the nerves in the rest of your body.

This is how we control our bodies. It is why the addicted brain can be problematic.

Neurotransmitters

Neurons talk to one another via synapses, or the gaps between themselves. A neuron will use these synapses to send information to its neighbours. It will do so by releasing a neurotransmitter, which crosses the synapse to attach onto the receiving neuron’s receptors. It’s like catching a tennis ball on one of those handheld Velcro pads that we all played with as kids.

Once received, a neurotransmitter will change the cell it attaches to.

The brain also contains molecules called transporters, which recycle neurotransmitters. They bring them back to the neuron they came from. This limits or ceases the signal between the neurons. The addicted brain can often suffer disruptions to these processes.

Neurotransmitters in the addicted brain

Drugs interrupt this signalling process. They disrupt or interfere with neurons’ sending, receiving, and processing of signals through neurotransmitters. In simple terms, this is why they make us feel and think differently.

Certain drugs’ chemical structures mimic those of the brain’s natural neurotransmitters. They can therefore attach onto and then activate neurons. Both heroin and cannabis work in this way. Though they mimic the chemicals found in your brain, they activate neurons differently to your natural neurotransmitters – again, this is why they change your brain state. They provoke abnormal messaging through your brain’s circuits.

Other drugs force your neurons to release larger than normal amounts of natural neurotransmitters or to prevent the normal recycling of these neurotransmitters. This in effect distorts and amplifies normal communication between your neurons. Cocaine and methamphetamine work in this way.

The addicted brain can therefore suffer. Long-term drug use can alter areas of your brain. They can change areas that are vital for healthy functioning and can push the compulsive behaviour and substance abuse that are symptoms of addiction.

Basal ganglia

Drug use can impact the basal ganglia parts of the brain. The basal ganglia are central to positive motivational forms, such as the pleasurable, life affirming effects of healthy habits like socialising, having sex, and eating well. They are crucial to forming habits and routines. These ganglia are a core part of what we often refer to as the brain’s reward or pleasure circuit.

Drug use overstimulates this circuit. This is where we get the highs associated with drug use. However, repeated use overexposes the circuits to a drug’s effects. It lowers sensitivity and makes it increasingly difficult to find pleasure in anything outside of the drug – and increasing quantities of the drug, at that.

Extended amygdala

The extended amygdala is central to managing feelings of stress such as anxiety, irritability, and unease. These are all feelings common to withdrawal symptoms as a drug’s effects peter out. This motivates a user to take more of the drug. It’s one of the main mechanisms of addiction itself.

This circuit grows in sensitivity as drug use intensifies. It is common to find those struggling with substance abuse disorder to use drugs not to get high, but simply to allay these symptoms of stress and anxiety.

The prefrontal cortex

The prefrontal cortex also suffers as a result of drug and alcohol use. It controls your ability to think and is crucial to planning, problem solving, decision making, impulse control, and many other logical strata of consciousness. It is the final part of the brain to mature, only coming into maturity in your early twenties. This is why children and teenagers often exhibit poor planning capabilities and impulse control. It also makes them far more vulnerable to drug abuse.

Drug use diminishes the prefrontal cortex’s ability and role. Rather, decision making processes are relegated to the basal ganglia and extended amygdala. An addicted person’s behaviour will therefore become far more compulsive and impulse related than logical and planned.

New research into the addicted brain

Treatments like deep brain stimulation hold a great deal of promise for helping people suffering from substance use disorder tread the path to recovery. They are a great cause for optimism in the fight to overcome addiction.

However, there is a lot left to discover. Importantly, we need to know which parts of the addicted brain we need to target with deep brain stimulation treatment.

There has been a lot of progress in this area in recent years. Researchers have been able to gain new insights by looking at patients who find themselves no longer addicted to nicotine after experiencing some form of brain lesion (like a stroke, for example).

This feeds into a new technique called lesion network mapping. Researchers at Brigham and Women’s Hospital have managed to map addiction remission to entire brain circuits, as opposed to specific brain regions. This flags a new target for treatment.

According to one of the paper’s authors, Michael Fox, MD, PhD, of the Department of Neurology at the Brigham:

“By looking beyond individual brain regions and, instead, at the brain circuit, we have found targets for addiction remission and are eager to rigorously test them through clinical trials. Ultimately, our goal is to take larger steps towards improving existing therapies for addiction and open the door for remission.”

The results were published in Nature Medicine, one of the largest, most well-established medical journals in the world.

How it works

This all relies on neuromodulation therapies. These include techniques such as transcranial magnetic stimulation, deep brain stimulation, and MRI-guided focused ultrasound. Techniques like these allow clinicians (in this case, those at the Brigham’s Center for Brain Circuit Therapeutics) to isolate and target specific brain circuits. They can then alleviate symptoms in ways unachievable through medication.

However, location is everything. Clinicians need to know where to target for this to work.

Previous studies have looked at lesion network mapping in patients who had seen essential tremors resolved. The study’s authors simply sought to use the same approach applied to addiction recovery and remission.

According to Juho Joutsa, MD, PhD, of the Turku Brain and Mind Center and Clinical Neurosciences at the University of Turku:

“Although we know a great deal about the neurobiological mechanisms in addiction, treatment options are still very limited. Our findings with essential tremor made us realize the potential of this approach to localize key brain circuits mediating symptom improvement.”

The study

The authors used data collected from two independent cohorts of participants. All participants were patients who had previously been addicted to nicotine, before then suffering a brain lesion, often from a stroke. The researchers compared the lesions in those who were able and those who were unable to quit smoking.

With this comparison in place, they then turned to the human connectome, a database, to map each lesion with its broader brain circuit.

The datasets that led to a remission of smoking addiction mapped to one specific brain circuit.

It didn’t stop here, though. The researchers also found that in a third lesion dataset, this one related to alcoholism, there was a reduced risk of alcoholism that they were able to map to a similar brain circuit.

This suggests a potential therapy. It suggests a targetable neural pathway for addiction in general, rather than to a single, specific substance addiction.

According to Fox:

“Although neuromodulation treatments using electricity or even brain lesions have shown promise in relieving substance addiction, the therapeutic target has been unclear. Now that our study has identified a target - a specific human brain circuit - we hope to test whether targeted neuromodulation to this brain circuit provides sustainable symptom relief to our patients.”

The story so far in treating the addicted brain

Treating the addicted brain has come a long way in recent years. However, so far, no specific medical intervention has proven to revert the brain back to a fully healthy state. Any research in this area is a good thing and may pave the way for more effective treatment in future.

However, as it stands, evidence-based treatments for addiction use a combination of medications and therapies to stabilise those that are suffering. Following this, the path of recovery is an endless journey with no set destination.

Many people do recover from addiction by utilising various therapies and recovery programmes. There is also an extremely large recovery community, whereby those in recovery support one another and help others to access recovery also.

In short, there is currently no quick and ultimate fix for treating the addicted brain. You can however join our recovery community, benefit from understanding addiction better and thrive within our Wellness hub.

Read more:

Understanding Addiction: Why Connection is Vital to Healing the Addicted Brain

References:

Science Daily: Researchers identify a brain circuit for addiction remission - https://www.sciencedaily.com/releases/2022/06/220613112046.htm