Building Infrastructure for Treating Adolescent Substance Use Disorder (Non-Accredited)

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 Neurobiology of Adolescent Substance Use and the Impact of Alcohol on the Adolescent Brain

SHANNON MOUNTAIN-RAY: Hello, and welcome today’s presentation, “Adolescent Substance Use: What’s the Deal?” I’m Shannon Mountain-Ray, Director of Integrated Care for the Adolescent Substance Use and Addiction Program at Boston Children’s Hospital. I’m extremely excited to be here today to talk about this very important topic.

This presentation will cover topics such as adolescent brain development and how it creates a special vulnerability for young people to develop substance use disorder. We’ll also talk about the impact of adolescent substance use on physical and mental health and give some important points that you can share with patients and caregivers about those risks.

To give a little bit of background, I come from the Adolescent Substance Use and Addiction Program, which we call ASAP for short. ASAP is a part of the Division of Developmental Medicine at Boston Children’s Hospital. ASAP started as an outpatient treatment program for young people who struggled with substance use. Our outpatient clinic consists of a multidisciplinary team of psychiatrists, developmental behavioral pediatricians, social workers, nurse practitioners, a wide range of administrative and research support. It is a hospital-based program, both at our Boston campus and our Waltham campus, and most recently providing extensive virtual care opportunities.

It is an outpatient treatment program, and it covers the broad range of substance use, from what we say, from experimentation to addiction, so for young people who may have only used substances once or twice, all the way to young people who are using every day over multiple years. Some of the services that are provided are things like comprehensive substance use evaluation, individual and group counseling, medications for substance use disorders, clinical drug testing, psychopharmacology, group therapy, and parent or caregiver guidance.

Our outpatient program has been around since 2000, and we have worked with a number of young people. But what we know is, of the 4.5% of adolescents between the ages of 12 and 17 who are diagnosed with a past year substance use disorder, only about 8.3% of them receive treatment. And so we were thinking, what else can we do? How else can we reach patients who are struggling with substance use?

Thus was born multiple integration efforts. Our primary care substance use integration program is the area that I focus on, and we’ll talk a little bit more about. In addition to that, we have our primary care telephonic consultation and virtual behavioral health treatment program. We provide school-based vaping groups and also have a partnership with our juvenile justice system.

Thinking about integration, we really focus on addiction medicine and primary care. How can we bring those two things together? Primary care tends to be where young people often present with issues related to substance use and behavioral health concerns, so we were thinking, how can we bring our outpatient model into pediatric primary care?

So what we looked at was bringing a clinical social worker with specialty training in substance use evaluation and treatment and having them integrate into the primary care setting as part of the multidisciplinary team. This is an office-based model as well as a virtual model and also provides an outpatient level of care from experimentation to addiction.

Care model focuses on caring for patients in the medical home, providing comprehensive evaluation, working with primary care providers to do things such as provide medications for alcohol, opioid, cannabis, and nicotine use disorders, and the social worker providing psychosocial treatment, including individual and group therapy, parent and caregiver guidance, and also working with the practice to provide referral in case coordination. In addition to the social worker integrating into the primary care practice, we also have support by the Addiction Specialty Program, so all of the ASAP providers provide some level of consultation to primary care providers for any questions or training needs that they may have.

So now, we’re going to switch gears, and we’re going to talk about James. James is a 17-year-old with no past medical or psychiatric history. He comes in for his annual well child visit. He’s a B+ student, and he’s finishing his junior year. He lives with his parents and is an only child. He’s a two-sport athlete.

Upon screen, James– excuse me– reports occasional drinking with friends on weekends but denies ever using illicit substances, and he’s starting to look at colleges. James receives his vaccines, and his PCP congratulates him on his hard work at school and his safe choices about drugs. One week later, James attends an end-of-the-year party with some friends. While driving home, his car jumps the curb, slams head on into a tree, and he’s pronounced dead at the scene. His BAC at autopsy is 0.24.

The reason that we use this as an example is because the primary care provider did a number of really great things. They screened for substance use. They got a sense of what was going on and provided some positive reinforcement about his safe choices around drugs. But there is more that primary care providers can do. In addition to talking about drugs, also screening and discussing alcohol and not only discussing the risks associated with the potential to develop a substance use disorder, but all of the correlates associated with adolescent substance use, many of which we’ll talk about in this presentation.

When we consider the leading causes of mortality amongst ages 10 to 24, we see the top three causes of death are things like unintentional injuries, which include things like motor vehicle accidents, poisonings, drownings, et cetera, with the next two being suicide and homicide. When we think about this in terms of adolescent substance use, we know that substance use in this age group increases the risk for all of those causes of death.

One area that we like to highlight is driving under the influence. Motor vehicle accidents remain the leading cause of death for young people this age. I have a slide here that specifically focuses on marijuana because in our experience, many young people have gotten the message around alcohol and driving and the risks of drinking and driving. Although it’s extremely important to continue to educate young people on the concerns around drinking and driving, it is also very important to specifically address areas such as cannabis use or other drug use while driving.

As you can see from this slide, high school seniors who smoke cannabis are two times more likely to receive a ticket and 65% more likely to get into a car crash than those who don’t smoke. We have often heard from young people who use cannabis and drive that they often feel that they actually drive better when they’re high. They focus more. They feel like they drive slower. But what we know from the research is, that’s not the case. Their reaction and coordination time are quite compromised, and the risk remains very high of an accident or some other negative outcome related to cannabis use and driving.

Some good news. When we look at the numbers and the prevalence of adolescent substance use, we see that adolescent substance use has actually declined in the last year amongst all age groups, high school age groups, so 8th, 10th, and 12th grade. When we dig a little bit deeper into the numbers, it’s important to understand some of the context. This is data that comes from the Monitoring the Future survey. This is a survey done with about 50,000 8th, 10th, and 12th graders every year. They ask a variety of youth risk behavior questions, including questions around substance use.

What we have demonstrated here are the data related to substances used by 12th graders in 2021, and we look at both the lifetime use and the past 30 day use. So when we consider lifetime use, this is the question that’s focused on, in your lifetime, have you ever tried any of these substances? And you can see that about 54.1% of 12th graders report alcohol use in their lifetime, and about 38.6% report cannabis use in their lifetime.

So the reason why we like to highlight this is because often we hear from young people and from parents and caregivers that all kids are using alcohol, every kid uses marijuana. And what we know is, that’s just not true. And when we look at the lifetime numbers, you can see that although adolescent alcohol use is normative by the time– trying alcohol by the time someone’s in 12th grade is normative, it is not normative for young people to be using cannabis by the time they’re in 12th grade.

When we look at other substances, you can see the percentages are much lower in terms of use. Alcohol, nicotine, tobacco, and cannabis are the most widely used substances in this age group by far. So when you’re thinking about screening young people for substance use, one of the things to consider is, what is the substance that they’re using? And if they report things like inhalant use or hallucinogen use or amphetamines or opioid use, they are in a higher risk category than the majority of their peers. So it’s helpful to understand the perspective of that.

Then we look at past 30 day use, and what we can see is, from those lifetime numbers, those numbers get cut in half. So this is asking a question around, in the past 30 days, have you ever used those substances? And we can have a better understanding of regular use patterns when we ask a question about past 30 day use. And you can see, again, those numbers get cut in half, so 54.1% of high school seniors say they’ve tried alcohol, but only 25.8% say they’ve used in the past 30 days.

The same is true for cannabis. 38.6% report lifetime use, and only about 19.5% report past 30 day use. And of course, again, looking at other substances, those numbers also go down significantly. So it’s helpful when you’re thinking about how prevalent is adolescent substance use, and you get reports from young people and parents about what’s happening. You can have a sense of where they fall on the spectrum.

We also know most drug use starts in adolescence, so this demonstrates past year initiates. And as you can see, there’s a significant jump between 12 and 13 and 14 and 15, and then again between 14 and 15 and 16 and 17, with the majority of initiation happening between the ages of 16 and 20. There is a significant decline by the time someone reaches 25, and then again when someone is 26 or older.

Some of the correlates of substance use during adolescence are things like intentional and unintentional injuries, emergency room visits, violence, legal issues, school issues, risky sexual behavior, sexual assaults, et cetera. So again, we worry about things like the development of a substance use disorder, but what we worry almost more about is the other things that can happen. Only about 10% of young people who use substances will go on to develop a substance use disorder, and we are very concerned about that. We’ll talk about why they’re higher risk during the phase of adolescence.

But what we also really want to highlight is, not only are we concerned about the development of a substance use disorder, but all of these other really negative experiences and potential outcomes. Adolescents are developmentally more vulnerable to developing substance use disorders and problems associated with substance use. It has everything to do with brain development.

So here’s a study that was done related to the age at first use and later risk for the development of a substance use disorder. If we look at the blue graph, we can see that young people who try to start drinking alcohol by the time they’re 13 have about a 50% chance of developing an alcohol use disorder. With every year they delay initiation, that risk goes down. So you can see it continues to go down, whereas if they wait to drink alcohol until they’re 21 or older, the risk of developing an alcohol use disorder goes down to about 9%.

The percentages are different with cannabis, but the trend is the same. So the younger you start using, the more likely it is you’ll develop a substance use disorder. So what is going on in that adolescent brain? Why are they more prone to developing substance use disorders or having negative effects related to adolescent substance use?

So one of the things we know is that the brain development continues into about the mid-20s. We used to think it stopped around age 10. That’s mostly because the brain, the size and the weight of the brain is at its maximum at 10 years and continues at that stage throughout life. So prior to the initiation of MRI imaging, we assumed that brain development stopped when the brain stopped growing.

What we now know is actually that adolescence is a critical period in brain development and that the brain continues to develop until the mid-20s. Brain develops from the back to the front, starting with a cere– excuse me– starting with a cerebellum and ending with the prefrontal cortex. The cerebellum is the area of the brain that’s related to things like walking, talking, motor skills, kind of maneuvering through the world in a physical way.

Next area of the brain to develop is this middle part of the brain. And I’m going to be specifically focusing on areas of the brain that are related to substance use, so that’s why we’re focusing on the amygdala. This is an area of the brain that’s related to things like emotional control, pleasure, reward, et cetera. Another area in the middle part of the brain that’s developing– it’s actually fully developed by the time someone reaches adolescence, is also the nucleus accumbens. This is also an area of the brain that’s related to pleasure and reward, and also things like learning and memory.

The final area of the brain to develop is the prefrontal cortex. This is in the front of the brain and is not fully developed until around 24 to 25 years old. And this is the area of the brain that’s really focused on things like executive functioning, impulse control, future-oriented thinking, et cetera.

If we’re looking at this in a little bit of a different way, we look at the limbic system, which includes the hippocampus and the amygdala, and that is fully mature by the time someone reaches adolescent– excuse me– adolescence and highly sensitive. So this is the area of the brain that focuses on things like emotional memory, fear response, pleasure, fight or flight.

And then that nucleus accumbens, also fully developed in adolescence and highly active and related to things like pleasure and reward and plays a major role in the development of substance use disorders. And then, again, that prefrontal cortex, which is not fully developed until late adolescence or early adulthood, and is responsible for all of these very important pieces of impulse control, decision-making, organizing, et cetera.

When we think about this in terms of substance use, I often like to use a car analogy. And think about this middle part of the brain, again, that limbic system that includes the hippocampus and amygdala and also the nucleus accumbens. I like to think about that as the gas pedal of the brain. So this is an area that’s highly sensitive and very responsive to pleasure and reward and fully developed by the time someone reaches adolescence.

And then we look at this other area of the brain, prefrontal cortex, and I like to think of that as the brake pedal of the brain. This is the area that helps us think through the decisions that we make and really kind of helps us to mitigate risk at times. So the tricky part about adolescence is that gas pedal is working very, very well, but the brake pedal isn’t fully developed. Think of the adolescent brain as a sports car. That gas pedal that you step on it just a little bit and it takes you from 0 to 60 very quickly is working very well, but that brake pedal is not.

The other thing that’s happening during adolescent development is extensive neuronal development. So this is a picture of before one reaches a process called blossoming, so all of a sudden in the brain, there is a phase that’s called blossoming where there’s extensive growth in terms of the number of neurons and neural pathways in the brain. About 11 for girls and 12 and 1/2 for boys, this thickening undergoes a process called pruning. So if you think of the neurons as being sort of a wily shrub, and it needs to be pruned down in order to work as efficiently and effectively as it possibly can.

So pruning starts, and in this phase, there’s a process of use it or lose it. So it’s really important for young people to use all the various parts of their brain to have all different kinds of experiences, physical experiences, artistic and creative experiences, intellectual experiences, relationships, social experiences in order to use as much of their brain as possible and really keep what they need. Because if not, the thickening undergoes this pruning, and you lose areas of your brain that you’re not using as well, and substance use can really affect this process.

At the same time, myelination is happening. So myelin sheaths that encase the nerve cells thicken like insulation on a wire to help the cell transmission be faster and more efficient, so lots of really important processes happening. So if we’re going with a car analogy, you might think, during adolescence, the brain is working to become an information superhighway, to be as efficient and as effective as possible.

So what’s also really interesting about where the gas pedal and the brake pedal fall is that we have another part of our brain called the reward pathway. This is an area of our brain that has evolutionary purposes. The reason why we have this area of the brain is really to remind us to do the things we need to do to survive, so things like eating, having sex to procreate, having social connections for protection, things like that. And what happens is, we have those experiences, and it triggers the reward pathway. The reward pathway gives off a very pleasurable experience.

And the idea is, because we’ve had that pleasurable experience, it will motivate us to want to continue to have those kinds of experiences. The interesting part related to substances is that substances hit that very same part of the brain, and so that triggers a pleasurable response. And for some– and we don’t know why some do and some don’t. We have some theories about genetics and other things that contribute to why someone might develop a substance use disorder, but we don’t really know how to predict this. It’s that when substances hit that area of the brain, they have a pleasurable response, and for some, the repetition and the reinforcement of that pleasurable response may lead to compulsive desire for substances. Hence, a substance use disorder.

I’m going to use an example to kind of bring all of this home, and I use cannabis specifically as an example because in our experience, cannabis tends to be the most widely misunderstood substance related to adolescent substance use. So we’ll start with talking about what’s in cannabis. Cannabis contains many cannabinoids, hundreds of cannabinoids. Some we know a little bit about, and some we know nothing about.

So some of the more widely known are things like delta-9-tetrahydrocannabinol, or THC. There’s also delta-8-tetrahydrocannabinol, cannabidiol, which is known as CBD, cannabinol, and some of these other cannabinoids. There is research being done. There will be more hopefully around the effects of these cannabinoids over time and specifically related to adolescent brain development.

What is the active chemical in cannabis? That is delta-9-tetrahydrocannabinol, also known as THC. It is the main active chemical, and cannabis potency depends on how much THC it contains. THC binds– excuse me– to the brain’s own cannabinoid receptor sites, so we’ll talk a little bit about what that means.

In our brains, we have a system called the endocannabinoid system. The primary purpose of this system is regulation. Often, we talk about it in terms of being a volume control. It helps to dial down neuron activity when it’s too strong, and it regulates several important areas, including things like pleasure, mood, pain, appetite, sleep, motivation, focus, memory, and attention. I often say, if you know young people who are using cannabis, you can tell that there’s often disruption in many of these areas. The endocannabinoid system also helps to keep neuron activity in balance, not underactive or overactive.

Your body produces its own cannabinoid chemical called anandamide, and anandamide binds to the cannabinoid receptors in your brain. I like to think of these receptors as cups and that our own endogenous chemicals are supposed to fill those cups and do their job and help to keep us in balance. Why do we have cannabinoid receptors? According to animal studies, they have shown that animals who do not have anandamides tend to experience things like more pain, difficulty controlling their appetite. They may be more anxious and less able to cope with stress.

What’s very interesting is, when you look at anandamide and compare it to THC, they look very similar. So what happens is, when you bring THC into your system, your brain thinks it’s anandamide, and it should go in those cannabinoid receptors. The difference is that when you use ananda– or when your brain produces anandamide, you do get a dopamine release. With cannabis, you get a much bigger dopamine release.

We think about this using a medical frame. We think of anandamide as a scalpel and THC as the hammer. Both dial down neuron activity to change neurotransmitter release, but THC has a much stronger and longer effect than anandamide on the cells. And THC interferes with anandamide function, so it can’t do its job properly.

There are THC binding sites all over the brain. There really isn’t any area of the brain that is untouched. Some of the things that are affected by cannabis are things like movement, sensation, judgment, reward, memory, coordination, and vision. Some of the acute pleasurable effects are things like mild euphoria, visual and auditory enhancements, and increased talking. Some of the adverse effects can be things like decreased coordination and reaction time, difficulty concentrating, and impaired memory and learning.

One of the concerning trends is that the content of THC in cannabis has increased over the years. As you can see when we look at this blue line, you can see between 1995 and 2018 the potency of cannabis products has increased with much higher levels of THC. Sometimes people can overuse or have a toxic level of THC in their brains, and this is when things happen, such as really extreme mood fluctuations, hallucinations, depersonalization, anxiety and panic, paranoia, and vomiting.

Something else to be aware of is cannabis withdrawal. So often working with young people, this is really important to highlight these points in order to help them prepare if they’re going to make any change to their cannabis use. If they are not prepared for this, often these things– they’ll experience these things, and then it will reinforce their desire to continue to use cannabis. So some of the withdrawal symptoms include things like restlessness and anxiety, increase irritability and anger, difficulty sleeping, decreased appetite, and sometimes weight loss.

And again, if you tell a young person, if you’re counseling a young person and they’re talking about making a change, either decreasing or stopping their cannabis use altogether, but often, if you ask young people why they’re using cannabis, they list many of the things on this list. So if they’re not prepared that they might experience this kind of withdrawal, they’re going to experience an increase in their anxiety, an increase in their irritability, much more difficulty falling asleep.

And then they’re going to say, well, see, it is helping me. This is why I’m using it. But what they need to know is, when they experience withdrawal, generally those symptoms are temporary and they dissipate over time. For those that don’t dissipate, we can get a much clearer sense of what the underlying issues are, and we can target the treatment to focus on those areas.

It was a study done in New Zealand that discussed persistent cannabis users showing neuropsychological decline from childhood to midlife. So this was called the Dunedin Study and had over 1,000 participants, which they followed from the age of 13 through 38 years old. At 13, it was prior to any initiation of cannabis use.

What they found was, when they broke it down between participants who had never used cannabis to those who had had three or more years of heavy use, and by heavy use, meaning multiple days over– excuse me– over an extended period of time, three years or more. When they went and they looked at the data related to IQ scores at 38 years old, what they found is those who had never used, their IQ score basically stayed around the same. But those who had three or more years of heavy use, their IQ decreased by almost 7 points.

THC is also known to reduce hippocampal neuron activation. With chronic exposure, neurons are gradually lost due to continual– excuse me– continual suppression. And those that use THC tend to have smaller hippocampuses and poorer memory. Teen working memory is also impacted by cannabis use, as you can see. Teens were asked to perform some level of a memory task. Those who don’t smoke at all did much better than those who use cannabis.

We also have ample research on the long-term effects associated with cannabis use in adolescents, including increased rates of psychosis, depression, anxiety, diminished life satisfaction and achievement, cognitive decline, and the development of substance use disorders. The American Academy of Pediatrics opposes legalization of cannabis because of the potential harms to children and adolescents.

This is just a really to highlight, if we can stop pretending that cannabis is harmless. This is directly sort of focused on adolescent consumption of cannabis and underscoring that with legalization, the misconception that drugs can’t hurt anybody– it can, especially young people. So what we know research tells us is that with legalization, the perception of risk decreases.

And we know this to be true, certainly with opioids. We also know this to be true with cannabis. And so it’s really important to consider that in how we’re talking to parents and young people about cannabis use and about substances in general, that their perception of risk– and we see it in multiple conversations we have with patients and families– that the perception of risk definitely decreases since legalization.

And some important points to take away. The adolescent brain is not fully developed. The reward pathway is highly sensitive during adolescence, and this increases the susceptibility to developing a substance use disorder. Substance use during adolescence– excuse me– substance use during adolescence can change the developing brain, increasing risks for learning, memory, and mental health problems.

Thank you for being with us today, and I hope you take some of this information away and can utilize it with your patients and families.