Why do People do Drugs?

Featuring Jonathan Morrow, M.D., Ph.D.

Transcript

Introduction (00:10):
Welcome to Michigan Medicine Presents, a wide ranging podcast series that will explore the progress in scientific research and innovation, historic roots, and the current state of conditions that affect us all. Join us for our first series, a three part look into the science of addiction.

Narrator (00:30):
The stats are easy enough to find online. Almost 21 million Americans have at least one addiction. The financial impact on the US economy is staggering. But the human toll, the impact on the life of the person struggling with addiction and the impact on the people around them, is immeasurable.

Addiction threatens careers and destroys marriages, and at its most basic level, any form of addiction harms a person's basic health. But most of us don't treat it like other conditions that affect your health.

Addiction is often stigmatized or hidden. And that may be part of why many of us know so little about what addiction actually is and how it works. And that's what this podcast is about. We're going to talk to the experts at University of Michigan Health and U-M Addiction Center - people whose careers are focused on better understanding addiction and how to better treat and live with addiction.

Narrator (01:28):
This is Michigan Medicine Presents, and we are talking about the science of addiction. Episode one: why do people do drugs?

Dr. Jonathan Morrow (01:38):
Well, there's many answers to that, that probably the easiest way to address that question is simply to ask people why are you using drugs? And when you do that, they'll answer many different things. They'll say, probably the most common answer is that it's fun. It's a pleasurable thing to do. But people will give other reasons like it's a way of treating their depression or relieving stress. Some people do it out of curiosity, sometimes to expand their mind, kind of open the doors of perception, or have some kind of adventure. Or learn more about themselves. And all of these reasons are probably true for various people. What they all have in common is that they're trying to reach some certain goal. The drug is supposed to do something for them that they consciously want. But there's evidence that that may not be true.

Narrator (02:41):
This is Dr. Jonathan Morrow, a psychiatrist with University of Michigan Health Addiction Treatment Services, or UMATS. Dr. Morrow also works with the U-M Addiction Center, and as he just explained, there are lots of reasons someone makes the choice to use a drug. But it is a uniquely human problem, right? Humans, the most complex form of life, we must have some very sophisticated reasoning that contribute to why we use and get addicted to drugs. After all, it's not like animals get addicted to drugs, right?

Dr. Jonathan Morrow (03:14):
Certainly some of these reasons you would have to be a conscious person, a human, really to have these kind of these kind of goals in mind. If you want to expand your self knowledge or open the doors of perception, right? That's not something a rat or a dog is going to do. But the problem with these explanations is that animals do use drugs. They use the same drugs we do. They love drugs. If you give them access to drugs in a way that they can use it, they'll do it all day. So that raises the question, are they really trying to expand their minds? I mean, do they have the same kinds of reasons for using drugs we do? It suggests that there may be a subconscious reason that's driving a lot of drug use. And if that's true for animals, it may be true for humans as well. We may not know the real reasons that we're using these substances.

Narrator (04:14):
There you have it, dogs can get addicted to drugs, just like people can. It's not just a sign of human weakness. If that's the case, how much control do we really have in whether or not we can become victim to substance abuse?

Dr. Jonathan Morrow (04:29):
We're in control and we're not in control. I mean, our brain is in control of what we're doing of drug use, just like anything else. But the question is whether we, our conscious self, how much we are in control of that behavior. So an example I like to give is just of breathing. You're breathing right now. But probably before I mention that you didn't notice that you were breathing. So you have to ask, why are you, if I asked you, why are you breathing? You might give me an answer. Well, I need to breathe so that I get oxygen into my blood and that will keep me alive. But the reality is, you weren't thinking about that before, but you were still breathing. Your brain stem was making you breathe, and all your brain stem knows is how much carbon dioxide is in your blood. It doesn't know anything about air. It doesn't know anything about oxygen. When your carbon dioxide levels get high, it just tells you to breathe and that's it.

Dr. Jonathan Morrow (05:27):
So that's not the real reason that you are breathing, but you have control over your breathing. I can breathe anytime I want. I can breathe in. I can breathe out. I can stop breathing. But the problem is, when I ask you to stop breathing for 10 minutes, you're going to have a problem. Now you're not in control. Eventually your brain stem is going to say, okay, I don't know what story you just told that says you don't have to breathe. You're going to need to tell a new story, because we're breathing.

Narrator (05:59):
We're breathing. Whether you want to or not, your body is going to kick in and take that breath. So using that reasoning, even if you know you shouldn't have a few more drinks, because you have an early morning tomorrow, is there a part of you that takes over and says, “I don't care that you have to work early. We are drinking.” Turns out there is.

Dr. Jonathan Morrow (06:19):
So dopamine is a chemical that's released into an area of the brain called the nucleus accumbens. This is part of the kind of the subconscious areas of your brain. And whenever you do something that meets some goal that is fulfilling for you, you're going to get a dopamine release into the nucleus accumbens. And what that signal is going to do is going to tell you, it's going to tell your brain anyway, do that thing again. No matter what it was, do it again. People think of it as a pleasure signal. We've known since the 1980s that it is not a pleasure signal. I'm not sure why people keep saying it's a pleasure, but it's more of a motivational signal. It tells you just do it again. And it's really whether you liked it or not. You'll get a signal to do it again if you get a dopamine release.

Narrator (07:15):
The nucleus accumbens. Now we have somewhere to direct our ire, and a worthy nemesis it is, because no matter which form of addiction we're talking about - the role of dopamine and the nucleus accumbens is universal.

Dr. Jonathan Morrow (07:29):
So one thing that we've learned from research on the neurobiology of addiction is that dopamine release in the nucleus accumbens is a key part of addiction. All drugs of abuse release dopamine into the accumbens. There's a lot of different drugs that people abuse and they have almost nothing in common chemically. Alcohol, cannabis, cocaine. They're very different molecules. The only thing they have in common is one way or another. They released dopamine in the nucleus accumbens. And really any reward that you have, any like food, sex, anything that you will pursue is also going to release dopamine in the nucleus accumbens. So a deeper question would be, what is the purpose of the nucleus accumbens? What does the nucleus accumbens do for us? And the nucleus accumbens is part of a larger circuit. It's a reward learning circuit. And the purpose of that whole circuit is to basically translate perceptions, emotions, experiences into a behavior or a response.

Narrator (08:41):
Can we turn it off? If the drug triggers the dopamine release and the dopamine is released into the nucleus accumbens, and then it starts calling the shots, against your will even, why does the nucleus accumbens have to be such a troublemaker?

Dr. Jonathan Morrow (08:55):
And so that's processed on different levels. So there's one level you just perceive the stimulus, say it's a beer bottle. Your brain recognizes that's a beer bottle. On another level, you have things like the amygdala hippocampus. Those are going to bring associations, memories, and attach that to whatever stimulus is. So the last time I saw this beer bottle, I was at a party. I was having a good time. And then the next level, you make a decision about what to do. That's where the nucleus accumbens lives. So the nucleus accumbens comes in at that decision level where you say, okay, I saw that beer bottle. Last time I saw it, I was having a good time. So now do I drink this beer bottle? Do I walk away? And then once you make that decision, it goes to another part of the brain where you actually prepare for the action and you do the movements to actually drink the beer or walk away or whatever it is.

Dr. Jonathan Morrow (09:54):
So the accumbens is making that decision. What am I going to do? And when you add dopamine to the nucleus accumbens, it's going to reinforce whatever you did. So you drink the beer, you get a dopamine surge, and that's going to say, okay, whatever sequence just happened, beer, memory, drink, we're going to make that stronger so that the next time you see the beer, you're more likely to drink.

Narrator (10:21):
You may be more likely to drink, but can you draw the line before things go too far? Lots of people enjoy drinking. With marijuana now legalized in many states, more people than ever before have access to legal marijuana. Is there a way for a person to know when they're at risk of going from regular, but casual use of a substance into addiction?

Dr. Jonathan Morrow (10:42):
So usually they don't know, because it's a subconscious process. We want to believe that we're in control all the time, even when we're not. But gradually you start to lose control and it gets to the point where you just, you can't really stop. You're making decisions that don't really fit with your larger goal. You're making a decision, for example, that it's more important to drink than it is to keep my job. Once you've gone that far down the road, I'd say you have an addiction. You've lost some level of control, because the motivation that you have is all getting funneled to the drug. Motivation that used to be for other things, is all getting funneled to the drug. Very hard to recognize from the inside. Whereas people on the outside can see, probably before you can, that your decisions are not yours anymore. It's a very tough message for people to hear.

Narrator (11:44):
It's as simple and as complicated as that. If you're in a place where all the motivation that used to go to your work, to your family, your art, your fitness is getting funneled to the drug, getting the drug, taking the drug, hiding your use of the drug, your decisions aren't really yours anymore. What kind of motivation does it take to break that cycle? How do you get to a place where you reach out for help?

Dr. Jonathan Morrow (12:10):
So some of it is just listening to other people who are probably telling you that this drug is kind of ruining your life. And it's also taking stock of the situation. And being honest with yourself about what this drug is doing. Because your conscious self is still, it's still there. You are watching this happen. So you'll have flashes of insight where you say, “Is this really what I wanted to do at this point?” If you can recognize that and give up some of the control that you believe you have, then you can get help with the addiction.

Narrator (12:57):
Do you have to get help or can you convince someone to stop? Can you trick your brain into not needing that dopamine surge, to ignoring the call of the nucleus accumbens? If you give someone enough negative consequences, can you just convince them to make the right choice?

Dr. Jonathan Morrow (13:16):
So there are ways that you can manage it. It's hard to really treat, people have tried this before where you try to have a negative experience associated with the drug use. This is the basic idea behind aversion therapy, which people still use, even though it clearly does not work. But the idea is that you have drug use and then you have a consequence to that. And the idea is that that's going to stop the drug use, because you have a bad experience. The neurobiology tells us that that won't work, because drugs release dopamine whether you have a good experience or a bad experience. You're going to want to repeat it no matter what the experience was. That's why drugs are addictive. And that's why other things are not addictive. If I eat good food and I have a pleasurable experience, I'm going to want to do that again. If I eat good food and I get sick off of it, I won't want to eat anymore, but that's not because I won't get the dopamine release. But if I have cocaine and I have a terrible experience, it will release dopamine, I will want to do it again. If I drink and I vomit all over myself, if I have legal charges, if I'm sexually assaulted, I still get a dopamine release because alcohol releases dopamine no matter what. So I'll want to do it again.

Narrator (14:44):
You want to do it again, and again. Can you become more addicted the longer you are dependent on a substance? And what other effects does prolonged substance use have on a person's body?

Dr. Jonathan Morrow (14:59):
There's the sub-cortical kind of unconscious parts of your brain, like the nucleus accumbens, and drug use will actually increase the activity in those areas of your brain. You also have prefrontal cortex in some kind of executive control areas. These are areas where your conscious self lives, where you're making your conscious decisions, and drugs, pretty much all drugs, will weaken those areas of the brain. They'll directly damage those areas. They'll weaken the connections between those kind of conscious prefrontal areas with the subconscious areas, and they will weaken your ability to control those urges over time. So, yeah, they do have long term consequences on the brain and it helps to reinforce that addiction cycle.

Narrator (15:56):
That was Dr. Jonathan Morrow in our three part series, The Science of Addiction. For more information about the University of Michigan Addiction Treatment Services, call (734) 764-0231, or visit uofmhealth.org/addiction. And don't miss the other two episodes in the series. You can find these and other Michigan Medicine podcasts at uofmhealth.org/podcasts, or by looking up the Michigan Medicine Podcast network wherever you stream your podcasts.

Connect with us

• Learn more about U-M Addiction Treatment Services (UMATS) and the U-M Addiction Center.
• Learn more about the University of Michigan Department of Psychiatry.