The Neuroscience of Addiction

What is Addiction?

Addiction is a chronic brain disorder characterized by compulsive substance use or behavior despite detrimental consequences.

What Causes Addiction?

Like most disorders, addiction cannot be attributed to a single cause. Studies have found genetic links, suggesting that up to 50% of addiction risk is heritable. However, this isn’t the full picture; someone might have a family history of addiction and never suffer from it themself. Addiction is often associated with personal trauma, as well as mental health conditions such as depression, anxiety, and PTSD.

Why Addiction is Misunderstood

Before we had an understanding of its neuroscience, addiction was a highly stigmatized condition that was seldom regarded as a legitimate disease. Due to their repetitive destructive behaviors, people with addiction were once labeled as simply lacking willpower. Despite substantial advancements in the psychology field, the stigma surrounding addiction remains prevalent. 

What Happens in the Brain?

When we look at the neuroscience of addiction, we are primarily focused on the brain’s reward systems. From an evolutionary standpoint, these reward systems have been designed to encourage behaviors necessary for our survival, like eating and drinking. When we engage in a behavior that is good for us, our brains release a surge of dopamine through our reward pathways. You might recognize dopamine as the neurotransmitter associated with happiness, and it is just that. 

The problem is that addictive substances (and behaviors) essentially “hijack” our brains’ reward systems. When we take an addictive substance or engage in an addictive behavior, our brains release a surge of dopamine that is substantially greater than that produced by typical natural rewards.

You might be familiar with the concept of neuroplasticity, or the concept that our brains change both functionally and structurally with experience. Over time, addictions form because our brains themselves begin producing less dopamine or reducing the available numbers of dopamine receptors. Because of this, we then need more of an addictive substance to produce the same pleasurable effect. This phenomenon is known as tolerance. 

Dopamine isn’t only implicated in reward pathways, but in memory and judgment as well. Addictive substance use becomes a habit via mechanisms in the amygdala and hippocampus, the areas of the brain associated with emotion and memory, respectively. Additionally, addictive substances can compromise the prefrontal cortex, the area of the brain associated with problem-solving and decision-making. Therefore, even though someone might intuitively understand that a substance is bad for them, simply abandoning that substance is not so simple.

Once the brain has adapted to an addictive substance over time, withdrawal can become extremely difficult. Without an addictive substance, the brain does not know how to function without its external source of dopamine, which can result in physical ailments, as well as complications with emotions, affect, and motivation.   

What Can Be Done?

Remember neuroplasticity? This is the quality of the brain that allows addiction to take root, but it is also the quality that offers the potential for healing. With appropriate treatment, people with addiction can rewire their brains so that, with time, they no longer need an addictive substance. Common treatments for addiction include:


• Individual therapy — Cognitive behavioral therapy (CBT) is common for helping individuals identify and address potentially destructive patterns in their thoughts and behaviors. Motivational interviewing, in which an individual works with a counselor to explore their feelings toward making changes, is also a typical therapeutic approach.

• Group or family therapy — Addiction most profoundly affects the person struggling with it, but it can also place a strain on their friendships and/or familial relationships. Because of this, group therapy sessions are designed to help both the individual with addiction and the overall functioning of the family or friend group of which they are a part. 

• Medications — Numerous FDA-approved medications address cravings for addictive substances and alleviate withdrawal symptoms. Several include naltrexone for alcohol use disorder and buprenorphine and methadone for opioid use disorder.

• Treatment programs — You might be familiar with organized treatment courses such as the “Twelve Steps” of the Alcoholics Anonymous program. These programs are unique in that they provide a community for people struggling with addiction, which can be beneficial for an individual’s motivation and overall social well-being.

Addiction is treatable, but these treatments are not always effective permanently. Since addiction alters individuals’ neurobiology so significantly, it is not uncommon for people to relapse and briefly return to their usual habits. This, however, does not mean that there isn’t hope for their recovery; it is a natural part of the recovery process. 

Takeaways

Addiction is not a weakness or a lack of willpower, but a legitimate, chronic brain condition that alters the brain on a chemical level. By understanding the neurobiological mechanisms behind addiction, we can become more compassionate, reduce stigma, and pave our way to effective recovery pathways.