For many people, there is an iconic commercial from the 1980’s about the influence of drugs on your brain. A man holds an egg, which is meant to represent your brain, has a hot skillet, which represents drugs, and he cracks the egg into the pan, which begins to sizzle and cook as he says “this is your brain on drugs. Any questions?”
This commercial was meant to be a way to both teach people about the negative impact that drugs has on your brain, as well as to motivate people stop using drugs from the fear that their brains will, in fact, be fried like that egg. The issue with this commercial is that it doesn’t explain what actually happens in the brain when drugs are introduced, and that over-simplification (drug use = fried brain) doesn’t jive with most people’s experience of drug use. So, what does happen in the brain when you use drugs or alcohol, and how can that lead to addiction?
This is your Brain
Let’s begin by understanding a little bit about how the brain works. This is a very simple model, but it will get to the heart of it all. Brains are made up of about 100 billion neurons, or nerve cells, which send messages to one another using chemicals called neurotransmitters. These neurotransmitters (there are about 100 of them that we know of now) tell the nerves to either activate, or turn off, which then goes on to the next nerve, and so on.
While many neurotransmitters are involved in substance use, there’s one that seems to play an outsized role in learning and behavior (including addiction). Dopamine is a neurotransmitter that is mainly found in an ancient part of the brain called the limbic system, which is located in the middle of the brain. This part of the brain is associated with things like mood, basic emotions, and rewards.
The limbic system activates when it sees something you like, and releases dopamine, which stimulates the brain and feels very good! For example, if you are a caveperson walking along and you see a bush full of blueberries, your limbic system will activate, flooding your brain with dopamine, and you’ll want to come back to that bush and even look around it for more blueberry bushes, because blueberries could be the key to your survival! This same process happens today … if you walk past a new store that has amazing looking doughnuts in the window, your brain releases a lot of dopamine (because we are still programmed to love fats and sugars, and doughnuts are delicious!).
This process is not really dependent on actual need; you might not be hungry when you pass that store, but you may still be pulled to get a doughnut in that moment. The dopamine system is all about “more,” and pushes you to do more or have more of the things that will release more dopamine. Why? In the old days (like, the really old days!), you needed to stock up on what you could when you had the chance, and we still function in this way today.
There’s something else that happens with dopamine. When dopamine is released, the brain takes in where you are, what you’re feeling and doing, who you are with, etc and associates that with the release of dopamine. So, if you have an amazing doughnut experience while your with a friend you don’t see that often, when you see that friend again you may be reminded of the doughnut and find yourself craving it. This is how dopamine connects with learning, and pushes you towards repeating actions again and again. (For a more in-depth look at this, check out the book The Molecule of More, by Daniel Lieberman.)
This is Your Brain on Drugs
Drug and alcohol use throw a bit of a wrench into the natural system of dopamine release and learning. Specifically, drug and alcohol use targets the dopamine system directly, bypassing all of the natural checks and balances that the brain has, and stimulates the release of dopamine at levels that you don’t usually see in natural releases. That is why cocaine is a more powerful reinforcer than a doughnut; it stimulates significantly larger dopamine releases which has a more powerful impact on the brain.
When the brain releases dopamine due to substance use, it continues to do what it always does: associate the dopamine release to what you are doing, how you are feeling, etc. Because substance use releases more dopamine than people are used to, the brain creates even stronger associations, especially with repeated use. So, someone who drinks when they feel stressed in order to relax might very strongly associate any kind of stress with the desire to drink. Over time, whenever they feel any kind of stress, their brains will start to search for dopamine release in the form of alcohol in an effort to achieve relaxation and for some an addictive cycle has begun.
You may be asking yourself, “this is interesting, but why is this important to understand?” That is a great question, and one that needs answering. When one has an understanding of how the brain is functioning and how it is feeding into problematic behaviors like substance use, it helps us understand that addiction is a natural brain process gone awry. It is not a problem with willpower, or an issue of weakness or moral depravity. A science based knowledge can help reduce the stigma associated with substance use by increasing empathy towards and understanding of people who are struggling with their substance use. The outcome of increased understanding and empathy is potentially an increase in people who are struggling being willing to get help!
The increasing understanding and empathy is particularly important, because one of the things that defines substance use disorder is repeated use despite negative consequences of use. From an outsiders point-of-view, a substance user’s behaviors might not make any sense. Why do they keep using when it is clearly ruining their life? When you begin to think about substance use as the brain’s search for more dopamine, you can begin to understand that their behaviors make sense, in their brain at least! This shift in understanding can be the difference between feeling burnt out by someone’s use and the ability to help them a little bit longer. And that extra time could be the difference between life and death.
The next time you notice yourself craving a doughnut, or a slice of pizza, or a glass of wine after work, think about how the dopamine system in your brain is working. And in that context, see if you are able to extend that to someone around you who is struggling with substance use and build a little more understanding and empathy for them. It might just feel good!