Dopamine and Addiction: What’s the Connection?

Addiction changes how the brain functions. It especially impacts the brain’s “reward system,” which is largely based on dopamine. This hormone is responsible for our pleasure response, along with other important functions like memory, attention, and mood.

Understanding addiction is an important part of recovery. Knowing there’s a physiological reason for your addiction can relieve some of the shame around it, so you can move forward in your healing journey. And gaining perspective on what’s driving your behavior can help you make lasting change.

A Peek Inside the Brain’s Reward System

We can experience pleasure from all kinds of activities, whether it’s exercise or scrolling social media. Our brain’s reward system is responsible for that feeling, and the desire to seek more of it.

How It Works

Your brain produces a chemical called dopamine. Dopamine is both a hormone and a neurotransmitter, meaning it’s used to send messages between your nerve cells. It’s tied to many functions, from mood regulation and memory to learning. It’s known as the “feel-good” chemical for the large role it plays in pleasure and motivation.

Dopamine is released along different neural pathways when we anticipate and experience something pleasurable. ((Trevor Haynes. (2018, May 1). Dopamine, Smartphones & You: A battle for your time. Science in the News. https://sitn.hms.harvard.edu/flash/2018/dopamine-smartphones-battle-time/ )) As it’s released, it affects dopamine receptors that live along these pathways, resulting in feelings of euphoria or happiness. This is known as the reward circuit.

The reward circuit activates areas of the brain that relate to focus, learning, taking action, and motivation.

The brain builds connections between a stimulus and pleasure that follows. ((Martinez, J. L., & Derrick, B. E. (1996). Long-term potentiation and learning. Annual Review of Psychology, 47, 173–203. https://doi.org/10.1146/annurev.psych.47.1.173)) Your reward circuit strengthens each time this process occurs. The more frequently it happens, the stronger your response is. Also called a reinforcing effect, it’s involved in how we form habits. ((Volkow, N. D., Fowler, J. S., Wang, G.-J., Swanson, J. M., & Telang, F. (2007). Dopamine in drug abuse and addiction: Results of imaging studies and treatment implications. Archives of Neurology, 64(11), 1575–1579. https://doi.org/10.1001/archneur.64.11.1575))

Cues leading up to pleasure are important. Dopamine makes us pay attention to markers that lead to a reward. This means dopamine activates before you even engage in a pleasurable activity.

This system helped early humans survive by rewarding beneficial behaviors, like eating. When it’s in balance, it allows us to stay focused, motivated, and happy. Dopamine imbalance is linked to mental health issues, like depression, and substance use disorders.

The Reward System at Different Stages of Addiction Recovery

Substances bypass the body’s natural dopamine production by directly flooding the reward system with it. Some substances do this more intensely than others:

• opioids
• stimulants
• alcohol
• nicotine

Stimulants like cocaine can release up to 10 times the amount of dopamine your body would naturally produce. ((The brain in recovery. (2017, January 28). Recovery Research Institute. https://www.recoveryanswers.org/recovery-101/brain-in-recovery/ ))

The Early Stages of Substance Use

The first time a substance is used, it creates a direct dopamine response. This intensity of this varies from person to person. According to neurotheology specialist Dr. Cyrus H. McCandless, “you can never accurately predict how much reward you’re going to get.” ((Misunderstanding dopamine: Why the language of addiction matters | Cyrus McCandless | TEDxPortsmouth. (n.d.). Retrieved September 30, 2022, from https://www.youtube.com/watch?v=aqXmOb_fuN4 ))

Your brain remembers everything leading up to a reward, so it can repeat the experience. This drives the desire to use more of a substance. As dopamine levels go up, serotonin, which helps us feel satisfied, goes down. This creates a cycle of wanting more while feeling less satiated.

This cycle doesn’t just apply to substance use. Altered dopamine pathways are seen in behavioral addictions, ((Grant, J. E., Potenza, M. N., Weinstein, A., & Gorelick, D. A. (2010). Introduction to behavioral addictions. The American Journal of Drug and Alcohol Abuse, 36(5), 233–241. https://doi.org/10.3109/00952990.2010.491884 )) including gambling, shopping, and sex.

Building Tolerance

Usually, brain chemistry returns to normal after a dopamine release. But continued substance use surges the brain with dopamine until it becomes overstimulated. Over time, the body wants to balance out, so it shuts down dopamine receptors. As a result, we won’t feel the same high from using the same amount of substances as before. This is how the brain builds tolerance. ((Volkow, N. D., Wang, G.-J., Fowler, J. S., Tomasi, D., Telang, F., & Baler, R. (2010). Addiction: Decreased reward sensitivity and increased expectation sensitivity conspire to overwhelm the brain’s control circuit. BioEssays : News and Reviews in Molecular, Cellular and Developmental Biology, 32(9), 748–755. https://doi.org/10.1002/bies.201000042 ))

Addiction

The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) has 4 criteria for classifying and diagnosing substance use disorders: ((McNeely, J., & Adam, A. (2020, October). Table 3, dsm-5 diagnostic criteria for diagnosing and classifying substance use disorders [abc] [Text]. https://www.ncbi.nlm.nih.gov/books/NBK565474/table/nycgsubuse.tab9/ ))

• impaired control
• social impairment
• risky use
• pharmacologic traits

The reward system plays a significant role in these.

Substances artificially change dopamine production. This can signal to the brain that substances are more important than other natural rewards. Eventually, natural rewards become less exciting and the brain learns to value substances ((MIT scientists discover fundamental rule of brain plasticity. (n.d.). MIT News | Massachusetts Institute of Technology. Retrieved September 30, 2022, from https://news.mit.edu/2018/mit-scientists-discover-fundamental-rule-of-brain-plasticity-0622 )) above all else.

Neuroplasticity, or the brain’s flexibility, ((Castrellon, J. J., Seaman, K. L., Crawford, J. L., Young, J. S., Smith, C. T., Dang, L. C., Hsu, M., Cowan, R. L., Zald, D. H., & Samanez-Larkin, G. R. (2019). Individual differences in dopamine are associated with reward discounting in clinical groups but not in healthy adults. Journal of Neuroscience, 39(2), 321–332. https://doi.org/10.1523/JNEUROSCI.1984-18.2018 )) also plays a part in addiction. We can get used to higher levels of dopamine following prolonged substance use. But an overstimulated brain no longer produces as much of it. Instead, it relies on substances.

Withdrawal

It’s not possible to keep up substance-induced levels of dopamine at all times. Drops in dopamine levels can contribute to withdrawal symptoms:

• depression
• anxiety
• cold sweats
• headaches
• and others

For many people, detox is the first step in the recovery journey. As substances leave your system, your body and brain recalibrate. Low dopamine levels during withdrawal can make this process difficult. But thanks to neuroplasticity, we can nurture our brain chemistry back to normal over time.

Note: Depending on the substance, detox can be life-threatening and shouldn’t be attempted alone.