Scott Webb (Host): Addiction is a multifactorial disease process that affects far too many Americans. My guest today is here to tell us more about the science of addiction, the history of our opioid crisis, and more. And joining me today is Dr. Jason Fields. He's an addiction psychiatrist with BayCare. Welcome to BayCare HealthChat. I'm Scott Webb.

Doctor, it's really nice to have you here today. We're essentially going to talk about the science behind addiction. And I've been looking forward to this one, especially this first question that I jotted down for you, because I've often wondered how addiction develops, right? You know, like, is it family history? Is it genetics? What is it? How does that happen to folks? So let's start there. How does addiction develop?

Jason Fields, MD: Well, addiction is a multifactorial disease process, and something to start with when we're talking about how does addiction develop is the fact that it is a brain disease. So, ASAM, the American Society of Addiction Medicine, has long recognized this to be the case, and it is now filtering down into the medical world that we need to approach addiction as a disease.

So what we know, I practice addiction medicine in an outpatient clinic, I've been practicing for about 15 years, and addiction is multifactorial in that if you have a primary relative, you are more prone to develop addiction disorders. Also, if you grow up with repeated traumas, you also are more likely to develop addiction. So there's definitely this nature and nurture aspect both to developing addictive disorders. For various reasons, people start to use mood altering substances. Whether it's to cope with a family situation, loss of a job, financial stress, whatever the personal stressor is. At some point in people's lives, unfortunately, usually during adolescence, when the brain is most vulnerable to developing addiction, people will start to cope by using substances.

Perhaps they have an undiagnosed mental health condition, like depression or bipolar disorder. These folks are significantly more likely to try to cope with their disease and develop addiction if they start to use mood altering substances with regularity. So whatever the substance is, whether it's marijuana or initially whether it's prescription opioids that are stolen from a parent, whatever the substance is, when used regularly enough and of long enough duration, the substance reprograms the brain.

Our brains have a pleasure center. And this is the science behind it. All of our brains have a pleasure center. And there is this amazing structure called the nucleus accumbens. And it is in the center of the brain, below the cerebral cortex, the big thinking part of the brain. And this nucleus accumbens sits in what is called the primitive part of the brain.

One might call it the reptilian part of the brain because all animals have this reward pathway that drives survival behaviors. For example, this is the part of the brain that releases a reward. It is a neurotransmitter, a substance called dopamine, that no matter what the substance, it releases dopamine, or the behavior that results in pleasure.

So, if you have food, shelter, if you have sex, if you are in love, you release dopamine. All of us release dopamine with these everyday activities that are part of our lives. Substances like THC, marijuana, opioids, alcohol, nicotine, cocaine, methamphetamine, all substances of abuse release lots of dopamine.

Scott Webb: Right.

Jason Fields, MD: And so in a vulnerable person who perhaps has a primary relative with substances, they are more likely to quickly develop, addiction because they respond rapidly to this reward from substances. Substances, like I just mentioned, release 10 times or more dopamine than the everyday behaviors I was describing, like food, water, sex, etc.

And so, unfortunately, the brain releases all of this dopamine and the person, especially if they're prone to addiction from a hereditary standpoint, quickly recruits other parts of the brain. And that is why this is a brain disease. Because they want to keep getting that reward.

And it also dismisses, it shuts down the frontal lobe of the brain and wakes up the reptilian primitive part of the brain, which so called “hijacks” the brain. And so your everyday activities like, should I go to work? Should I not spend this money? Should I not drive while impaired? The risky things that people do in active addiction. They're in a disease state where their forebrains are shut down and this reward pathway, this reward center, is lit up and in an overdrive, kind of driving all of our behaviors. So that's how addiction develops, in this pleasure center of the brain.

Host: Right. Yeah, I wanted to ask you about the relationship of addiction to brain changes, because that's what it sounds like we're talking about, these changes in our brain. You say the hijacking that goes on. Maybe you can sort of delve into that a little bit, that relationship.

Jason Fields, MD: So you have neural pathways in our brains. So, our reward pathway that I just described in the frontal lobes and other areas of the brain, they all kind of have a specific function. Our frontal lobes is our executive functioning, very developed compared to other animals, right? That's why we're so called higher order animal.

And, the frontal lobes do their job and help us make good decisions. In active addiction, when the brain is so called hijacked, there is a recruitment of other areas of the brain. For example, near that nucleus accumbens, where the dopamine is released in exponential amounts with substances, there is a structure called the hippocampus.

And the structure called the amygdala. And the hippocampus remembers the pleasure associated with using substances, especially initially when people experience a big dopamine release. So that hippocampus remembers that and makes it difficult in an active disease state where you continue to use or say you're in an environment where you used to use. You're out of control, the forebrains are shut down, and that pleasure center is in overdrive and the hippocampus does its job.

The amygdala helps us program and remember emotions associated with using. And the amygdala, the hippocampus, the nucleus accumbens, the ventral tegmental area, all of these so-called primitive brain structures, that is what is in overdrive with addiction. And you can actually do a PET scan of the human brain during active using versus a so-called normal brain in a non-addicted person. And upon presentation of the substance of, let's say, cocaine, if that's what they're addicted to, you can actually see that the cocaine addict has a very lit up primitive brain structures, reward pathway structures that I just described, while the forebrains, where we do our executive structure, are very quiet and dark during active addiction, versus cocaine presented to the non-addicted individual, their forebrains don't shut down in activity. So there is truly this phenomenon occurring with repeated substance use.

Host: Yeah, it's really interesting, and I'm sure, Doctor, there are, let's say, short- and long-term effects of addiction, right, whether it's changes in life behaviors, body chemistry, whatever it might be. Maybe you can sort of take us through that timeline. What are some of the short- and then long-term effects?

Jason Fields, MD: Well, the short-term effects are that the individual starts to change their behaviors. So active addiction is manifested in behaviors. I think that's why addiction as a disease is really stigmatized. Because what you see in an adolescent girl that starts to have trouble with marijuana or prescription pills is that she will withdraw from friends that she used to hang out with.

Her academic progress may start to wane. Things that she used to have interest in suddenly aren't so interesting to her. So this is an example. So you start to see it manifested in behaviors. The brain itself is upon presentation of the substance of choice, releasing, in early addiction, a lot of dopamine. A lot. Driving these behaviors, okay? And, so everything takes second place to getting the substance, not running out of the substance, and continuing this reward that the person experiences.

Over the longer term, the brain adapts, and new pathways are laid down. Literally new neuron connections occur that reroute the circuitry of the brain and bypass the forebrain.

And that's why we see the activity of the forebrain shut down in addicted persons over time. Also, just like keeping itself in check, the brain starts to decrease the amount of dopamine receptors and not have the response in more chronic addiction. Let's say the person's been using one year or more, you start to see changes where the brain adapts and doesn't give the same response to the same amount of drug.

It's a phenomenon called tolerance. So that is more of a chronic situation that occurs with the brain.

Now there's good news, okay? Even when tolerance occurs and those neural pathways are rerouted in favor of the reward pathway of the brain, changes can occur, the brain can heal itself, and that's when you get into what is effective treatment for addiction.

Host: Yeah, and I know, Doctor, opioids have been in the news a lot, opioid crisis in America, perhaps globally, there's been lots of TV shows and films about how this all happened. Maybe you can talk a little bit about the guidelines and how they've changed over time.

Jason Fields, MD: Absolutely. So, we are still in the wake of an opioid crisis. We're in the so called third wave of the opioid crisis. So prescription opioids, or the initial wave, the first wave of the opioid crisis in America that began in the 1990s with unregulated so-called pill mills dispensing lots of prescription opioids.

And providers didn't have any way to check if patients were doctor shopping. So you might have seen some of the documentaries that were very good about the oxycodone crisis and the manufacturers of oxycodone. And what literally happened is, patients when they were prescribed the opioids, the physicians weren't as attuned to the dangers and didn't understand how addictive oxycodone was.

It became quickly clear with all of the crime and all of the deaths that were occurring, and we found ourselves in the wake of a prescription opioid crisis in the early 2000s. So, once that was discovered, I started practicing addiction medicine in 2008, and what we initially saw when we were treating patients was people addicted to prescription opioids.

In 2011, the state of Florida came into tune with the rest of the country and a prescription drug monitoring profile was established, the so called PDMP. In Florida it's called E-FORCSE. And now, it is law that any dispenser of any medications control substances like prescription opioids, they have to register it in the PDMP.

So the physician knows when they're treating a patient with addiction, they can tell if they have received prescription opioids. And it helps family practitioners and primary care providers more safely prescribe. When this tool was available to us from 2011 on, and legislation came into play in Florida and across the rest of the country that shut down pill mills, for example, they used to only be able to take cash, they didn't have to have a physical exam on, but when they became scrutinized by law to regulate these pill mills, they shut down, they couldn't survive.

And what you had was a lot of individuals addicted to opioids that lost their drug of choice, they couldn't get the prescription opioids. So they went into the second wave of the opioid crisis in about 2012, 2013, and that was with heroin. Heroin, which was a problem opioid back in the 70s and 80s, came back because it was cheap, readily available, and off the street. You didn't have to go through a physician to get it. You didn't have to buy other people's drugs.

Unfortunately, in about 2016 or so, fentanyl started to enter the drug market and it was by design. Drug dealers, makers of the fentanyl in China and Mexico and elsewhere, introduced fentanyl to keep the demand going because it is a hundred times more potent than morphine, fentanyl is.

And so, you had these individuals that once fentanyl was introduced, there were a lot of deaths. But as tolerance, that phenomenon we talked about, occurs, people primarily go to fentanyl. With fentanyl, which is the synthetic introduced in 2016 or so, the number of deaths exponentially increased, unfortunately, across the United States, as overdoses occurred.

And other synthetics started to work their way into the drug supply, too. So fentanyl isn't the only dangerous synthetic that we're weary of out there. Now, fentanyl drives most opioid addictions. And is a major problem because of its potency. So, that is the three waves of the opioid crisis.  

Host: Dr. Fields, really appreciate our discussion today about the science behind addiction, the history of the opioid crisis. Looking forward to part two of our series and we’ll talk about recovery. Thanks so much.

Jason Fields, MD: You're so welcome.

Host: If you or a loved one is experiencing addiction, get connected with a BayCare provider at (877) 850-9613 or call 2-1-1 for resources.

And that wraps up this episode of BayCare HealthChat. Always remember to subscribe, rate and review this podcast and all of the other BayCare podcasts, so we can share the wealth of information from our experts together. I'm Scott Webb. Stay well.