The Neuroscience Behind Addiction

An in-depth look at how addiction affects the brain.
Artist render of brain neurotransmitter
3 min
November 5, 2023

Understanding addiction is complex, as it encompasses many emotional, psychological, and physiological aspects. The American Society of Addiction Medicine (ASAM) defines addiction as a treatable, chronic medical disease that impacts the brain and behavior. To delve into the intricacies of addiction, it’s critical to explore what occurs in the brain on a neuro-scientific level.

The Role of Neurotransmitters

Neurotransmitters are chemicals that facilitate communication between neurons (nerve cells) in the brain. Dopamine, a key neurotransmitter, is often called the “feel-good hormone” because it’s associated with pleasure and reward. In the case of addiction, substances or behaviors can cause a surge in dopamine levels, reinforcing the rewarding feeling.

The Reward Circuit

Our brains are wired with a reward circuit designed to reinforce behaviors crucial for survival, such as eating and procreating. The nucleus accumbens, part of the reward circuit, gets activated when you engage in these activities. When an addictive substance is used, it artificially stimulates the reward circuit, causing it to release up to 10 times the amount of dopamine normally produced. This produces intense feelings of pleasure but also disrupts regular brain function.

Development of Tolerance

Over time, the brain adapts to the excess dopamine by reducing its sensitivity. As a result, people need to consume more of the substance or engage in the behavior more frequently to achieve the same high, leading to tolerance.

Dependence and Withdrawal

Physical dependence occurs when the brain becomes so accustomed to the substance that it can’t function normally without it. Withdrawal symptoms ensue when the substance is not present, leading to a cycle of increased use and dependence.

The Prefrontal Cortex and Decision-Making

The prefrontal cortex, responsible for decision-making and impulse control, is also affected by addiction. Altered neurotransmitter activity in this area can lead to impaired judgment, making it more challenging to resist the urge to use the substance.

Treatment Approaches

Understanding the neuroscience behind addiction has led to more effective treatments, including medications that target neurotransmitter activity and behavioral therapies that aim to reshape neural pathways.


The brain’s complex interplay of neurotransmitters, neural circuits, and various regions makes addiction a multifaceted issue. Advances in neuroscience are continually shedding light on how addiction manipulates the brain and how best to treat it.

If you or someone you know is struggling with addiction, understanding the neuroscience behind it can be the first step toward effective treatment and recovery.

You can consult the ASAM website or other government-based domains specializing in addiction treatment for additional resources and support.