The Neurobiology of Addiction

“You’re in the desert and it’s day five with no water and your organs are shutting down and you’re literally going to die. And I hand you a bottle of water. But I tell you if you drink this, I’m going to take your kids, your job, your wife, your house -- you would drink the water. Everyone would.  There’s no macho person out there who thinks they can withstand this, it’s not possible.” “So you drink the water, satiate that tiger, the midbrain, so that the urge to live is taken care of, and then other part of your brain comes back on line and starts going, ‘Oh my God, I can’t believe I gave up all that stuff for water,’ and you start trying to manipulate me into giving your stuff back. That’s exactly what addicts do.” – Dr Nicole Labor

When someone mentions addiction, what do you think of? Back in the 1930’s, when research on what fuels addictive behaviors began, the consensus was that people with addiction were somehow “morally flawed” or simply didn’t have the willpower to quit. Many people still hold this stigmatized view of addicts, although science has now shown us that this is not the case. If you saw someone with heart disease, would you look down on them and believe they are “morally flawed”? Probably not. The same way heart disease attacks your heart, addiction attacks the brain. The disease of addiction changes both the structure of the brain and how it functions. If you look at an addicted brain vs. a non-addicted brain, the differences are glaring.

So, let’s look at the brain! The brain has an area called the frontal cortex and another called the midbrain. The frontal cortex makes you, you. It’s the seat of self and personality and where our conscious choice and willpower lie. I’ll say that again, this is part of our CONSCIOUS brain. Now the midbrain on the other hand, is our primitive, subconscious brain that holds the key to survival. We have NO CONTROL over the midbrain. It acts immediately with no planning or thought of future consequences. The midbrain comes on when life is threatened. Eat, kill, sex. That’s the midbrain. All drugs (and alcohol) work in the midbrain.

Our brains are equipped with a nice little neurotransmitter called dopamine. When we experience pleasure our brains get increased dopamine. Every addictive substance attaches to different neurotransmitters, but the one they all have in common is dopamine. With alcohol and other drugs, the brain gets absolutely flooded with dopamine. Over time, the brain figures out that it doesn’t really need all of the dopamine receptors it has naturally because it’s constantly being given more, and they basically get killed off. This significantly increases the brains “pleasure threshold”, basically the level that needs to be reached for us to derive pleasure from something. So things that you used to enjoy, like music, sports or gardening, are no longer pleasurable. We can’t reach that pleasure threshold from natural sources anymore. That’s also where tolerance comes into play, you need more and more of the alcohol or drug each time to feel the same pleasure.

Ok, now, back to the midbrain. When the midbrain is repeatedly exposed to a highly rewarding chemical (flooding it with dopamine), it starts to think that this chemical is necessary for survival. Because truthfully, we need pleasure to survive. But probably from music or gardening, not heroin. All drugs work in the midbrain, this includes alcohol. In true addicts, the midbrain is lit up like a Christmas tree and there is very very little activity in the frontal cortex. People who use alcohol and other drugs and don’t get addicted show much more activity in the frontal cortex and are able to use their judgment, morals, values, and power of choice.

So who decides who gets addicted and who doesn’t? Genetics. Epigenetics. There’s a gene for lung cancer, there’s a gene for heart disease, there’s a gene for addiction. Most people have at least one of these addiction genes, many people have more than one. Ever wonder why some people can smoke a pack a day for 30 years and never get lung cancer while someone who has never smoked a day in there life does? That pack a day smoker just didn’t have the gene, or those 10,000+ packs just weren’t enough to turn their gene on. Addiction genes are activated by specific drugs in specific quantities, and everyone is different. Your gene could be activated by 1 beer, while someone else might use cocaine 12 times before it gets activated. You just don’t know, until you know.

This is a very brief glimpse at some of what happens inside the addicted brain. If you want more information and details, check out our podcast, MindTap. And if you, or someone you love is struggling with addiction, please call the ADM Board addiction helpline at 330-940-1133.  

Written by: Grace Williamson, MA, LPC