Never Enough: The Neuroscience and Experience of Addiction | Judy Grisel | TEDxPSU

Summary

This script addresses the alarming rates of substance use among young people, highlighting the impact of early exposure on developing substance use disorders. It delves into the brain's reward system, illustrating how drugs like marijuana can disrupt the brain's natural homeostatic balance, leading to tolerance and dependence. The speaker's personal journey from addiction to neuroscience research underscores the complexity of addiction and the ongoing search for solutions.

Takeaways

• 🔢 High school students are at significant risk of substance abuse; 70% have consumed alcohol, half have tried illegal drugs, and close to that number have used nicotine.
• 🚫 Early exposure to substances is a major risk factor for developing substance use disorders, with those starting at 14 having seven times the risk of developing an alcohol problem compared to those starting at 21.
• 🧠 The adolescent brain is naturally inclined towards risk-taking and novelty-seeking, which has evolutionary benefits but also primes them for substance experimentation.
• 💉 The speaker's personal story illustrates the severe consequences of substance abuse, including homelessness, hepatitis C, and the need for treatment.
• 🎓 The speaker's academic pursuit in neuroscience reflects the complexity of addiction, which remains an unsolved problem despite extensive research.
• 🌐 Addiction is characterized by craving, compulsive use, tolerance, and dependence, influenced by genetic, environmental, and developmental factors.
• 🧬 Genetics play a role in addiction, with certain tendencies like novelty-seeking and risk-taking being more prevalent in some individuals.
• 🌳 Environmental factors such as access to drugs and stress levels can contribute to the development of addiction.
• 👶 Adverse childhood experiences can prime an individual for addiction, as they may use substances to cope with early trauma.
• 🏠 The concept of homeostatic emotional baseline is introduced, explaining how substances can disrupt this balance and lead to addiction.
• 🍔 The speaker uses the analogy of finding 'bacon' to explain how the brain's endocannabinoid system responds to rewarding experiences, and how THC from marijuana disrupts this natural process.
• 💡 Regular marijuana use can lead to a diminished sense of reward and pleasure, as the brain adapts by reducing the interaction sites, leading to a lack of interest in previously enjoyable activities.

Q & A

What percentage of kids will have drunk alcohol by the time they graduate from high school?

70% of kids will have drunk alcohol by the time they graduate from high school.

What is one of the primary factors in developing substance use disorders?

One of the primary factors in developing substance use disorders is early exposure to substances.

How much more likely is a person to develop an alcohol problem if they start drinking by age 14 compared to waiting until 21 or later?

A person who starts drinking by age 14 is seven times more likely to develop an alcohol problem compared to someone who waits until they are 21 or older.

Why do adolescents take risks according to the speaker?

Adolescents take risks because they are primed for high risk-taking and novelty seeking, which historically benefited human populations by balancing progress and caution.

What are the characteristics of addiction mentioned in the script?

Addiction is characterized by craving, compulsive use, tolerance (the drug works less well over time), and dependence (feeling less good than normal without the drug).

What percentage of the risk of addiction is attributed to genetic factors?

About half of the risk of addiction is attributed to genetic factors.

How does early adverse experiences influence the development of addiction?

Early adverse experiences can prime a person for developing an addiction as they may use substances to cope with stress.

What is homeostasis in the context of feeling states?

Homeostasis in the context of feeling states refers to a baseline feeling state that is actively maintained by the nervous system, allowing individuals to gauge if something good or bad happens.

How does the brain adapt to regular substance use according to the speaker?

The brain adapts to regular substance use by developing tolerance, meaning the substance has less effect over time, and by causing dependence, so that when the substance is not present, the person feels worse than their normal baseline.

What happens to the brain's endocannabinoid system with frequent marijuana use?

Frequent marijuana use causes the brain to lose interaction sites in the endocannabinoid system, making everything seem less interesting and motivating without the drug, and potentially leading to permanent changes in brain function.

Outlines

00:00

📊 The Statistics and Risks of Early Substance Use

This paragraph opens with startling statistics on the prevalence of substance use among high school graduates, highlighting that a significant percentage will have tried alcohol, illegal drugs, or nicotine. It emphasizes the critical issue of early exposure to substances, noting that those who start young are at a higher risk of developing substance use disorders. The evolutionary perspective suggests that risk-taking and novelty-seeking behaviors in adolescents, although beneficial historically, now contribute to substance use. The paragraph also mentions the developmental gap between reward pathways and caution, contributing to identity formation and increased risk-taking.

05:02

🚨 Personal Story of Addiction and Recovery

The speaker shares a personal narrative, detailing a journey from early substance use at age 13 to severe addiction. They describe the consequences, including expulsion from schools, homelessness, and health issues like hepatitis C. A turning point comes with entry into a treatment center at 23, leading to a realization about the necessity of abstinence. This experience spurs the speaker to pursue a PhD in neuroscience to understand addiction better. Despite extensive research, they highlight the complexity of addiction, driven by craving, compulsive use, tolerance, and dependence, and influenced by genetic, environmental, and developmental factors.

10:04

🔄 Understanding Homeostasis and Its Disruption by Substances

This paragraph introduces the concept of homeostasis, the body's maintenance of a stable internal state, which fluctuates with positive and negative experiences. The speaker explains how substances like alcohol and drugs temporarily alter this state, often at a cost, leading to feelings of discomfort when returning to baseline. The brain adapts to repeated substance use, developing tolerance and dependence. They use personal anecdotes and a broader context to illustrate how these adaptations can lead to a diminished ability to experience pleasure without substances, emphasizing the challenge of maintaining normalcy after addiction.

🍃 The Effects of Marijuana on the Brain

Focusing on marijuana, the speaker explains how its active ingredient, THC, interacts with the brain's endocannabinoid system, which is involved in various functions like learning, memory, and motivation. They describe the natural release of neurotransmitters like anandamide in response to significant experiences and compare it to the widespread and unnatural activation caused by THC. This widespread stimulation leads to a brain adaptation, reducing interaction sites and altering how experiences are processed. The speaker shares personal experiences of how marijuana use made everything seem interesting but eventually led to a lack of motivation and pleasure in regular activities, highlighting the long-term impact on the brain.

🧠 The Long-Term Consequences of Regular Marijuana Use

The final paragraph delves deeper into the consequences of regular marijuana use, particularly during development. It explains how the brain compensates for constant THC exposure by reducing interaction sites, leading to a permanent change in how information is processed. This adaptation results in a diminished ability to find reward and pleasure in everyday activities. The speaker concludes with a reflection on the broader impact of substance abuse, noting it as a leading cause of death for people under 50, and how regular use of addictive drugs can lead to states opposite to those desired. They end with a personal note on the loss of interest and enjoyment in life that came with long-term marijuana use.

Keywords

💡Substance Use Disorders

Substance Use Disorders (SUDs) are medical conditions characterized by an uncontrollable urge to use substances like alcohol or drugs, despite harmful consequences. The video emphasizes that early exposure to substances is a significant risk factor for developing SUDs, highlighting the importance of preventing early substance use among adolescents.

💡Early Exposure

Early exposure refers to the initial introduction to substances such as alcohol, drugs, or nicotine at a young age. The video discusses how early exposure significantly increases the risk of developing substance use disorders later in life. For example, starting to drink alcohol at age 14 increases the likelihood of developing alcohol problems.

💡Risk-Taking

Risk-taking is the tendency to engage in behaviors that involve potential dangers or losses. The video explains that adolescents are naturally inclined towards risk-taking due to evolutionary benefits, which can lead to experimentation with substances. This behavior, while historically beneficial for survival, poses modern risks for developing SUDs.

💡Novelty Seeking

Novelty seeking is the desire to experience new and exciting things. The video notes that adolescents have a high tendency for novelty seeking, which can drive them to experiment with drugs and alcohol. This behavior is linked to the brain's development and its impact on identity formation and motivation.

💡Reward Pathways

Reward pathways are neural circuits in the brain that reinforce behaviors by releasing pleasurable chemicals. The video describes how substances like alcohol and drugs hijack these pathways, leading to increased use and eventually addiction. Adolescents' brains develop reward pathways faster than cautionary ones, making them more susceptible to addiction.

💡Tolerance

Tolerance is the process by which the body becomes less responsive to a substance, requiring higher doses to achieve the same effect. The video explains that tolerance is a hallmark of addiction, where over time, the pleasurable effects of drugs diminish, leading users to consume more to attain the desired high.

💡Dependence

Dependence is a state where the body relies on a substance to function normally. The video discusses how dependence develops when regular drug use alters the brain's homeostasis, causing withdrawal symptoms when the substance is not present. This creates a cycle of compulsive use to avoid negative feelings.

💡Homeostasis

Homeostasis is the body's ability to maintain a stable internal state. The video uses this concept to explain how the brain regulates feelings and returns to a baseline after positive or negative experiences. Substance use disrupts this balance, leading to long-term changes in how pleasure and reward are experienced.

💡Endocannabinoid System

The endocannabinoid system is a group of endogenous cannabinoid receptors located in the brain and throughout the body. The video highlights how THC from marijuana interacts with this system, creating feelings of euphoria. However, chronic use can disrupt normal brain function and lead to decreased motivation and pleasure in everyday activities.

💡Adverse Experiences

Adverse experiences refer to traumatic or stressful events that negatively impact a person's development. The video mentions that such experiences, especially in childhood, can increase the likelihood of substance use as a coping mechanism. These experiences can alter brain development and make individuals more prone to addiction.

Highlights

By the time they graduate from high school, 70% of kids will have drunk alcohol, half will have tried an illegal drug, and close to that many will have smoked or vaped nicotine.

One in five will have used prescriptions off-label, and early exposure is a primary factor in developing substance use disorders.

The majority of people with substance use disorders began using before they were 18.

Starting to drink alcohol by age 14 increases the chance of developing an alcohol problem by seven times compared to waiting until 21 or older.

High risk-taking, novelty-seeking, and low respect for authority are evolutionary traits that benefited population survival and individual identity development.

There's a developmental gap in the brain where reward pathways and motivation develop faster than caution, impulse control, and abstract reasoning.

Around 10,000 people die every day from drug abuse worldwide.

Personal story: The speaker began drinking at 13, used various drugs, became homeless, contracted hepatitis C, and eventually sought treatment after a decade of substance abuse.

Addiction is characterized by craving, compulsive use, tolerance, and dependence, with risk factors including genetics, environment, and developmental factors.

Early adverse experiences and adolescent exposure significantly increase the risk of developing an addiction.

The brain maintains a homeostatic feeling state baseline, which fluctuates with good and bad experiences.

Alcohol and drugs can temporarily alter this baseline, causing initial euphoria followed by a return to or below baseline, leading to tolerance and dependence.

Marijuana's active ingredient THC interacts with the brain's endocannabinoid system, affecting areas associated with learning, memory, motivation, and reward.

Regular marijuana use during adolescence can permanently alter brain development and how information is processed.

Substance abuse can lead to a loss of interest and motivation in previously rewarding activities, contributing to a cycle of despair and dependence.

Substance abuse is the number one killer for people under 50, and regular use of addictive drugs leads to feeling states opposite to those initially desired.

Transcripts

[Music]

[Applause]

by the time they graduate from high

school 70% of kids will have drunk

alcohol half will have tried an illegal

drug and about close to that many will

have smoked or vape nicotine one in five

will have used prescriptions off-label

these numbers are critical because one

of the primary factors in developing

substance use disorders is early

exposure it's a fact that the majority

of people who have a substance use

disorder began using before they were 18

for instance if you start drinking by 14

you have seven times the chance of

developing an alcohol problem then you

would if you had waited until you were

21 or longer so why do kids take these

risks well they're primed for those

risks and in fact through most of our

evolutionary history high risk taking

and novelty seeking and low respect for

adults and authorities have benefited

the population as a whole it's great to

have a bunch of contrary risk takers

living alongside more cautious folks so

that we have a balance between progress

and caution and these changes are also

really good for them individually

because it helps them to develop their

own identities this tendency to

experiment and take risks is built into

the way the brain develops there's a gap

between the development of reward

pathways and motivation which happens

quicker than those for caution and

impulse control and abstract reasoning

and that serves them again by helping

them to develop their identities and it

serves the rest of us about 10,000

people die everyday from drug abuse

around the world and I should have been

one of those I took my first drink at 13

and was off to the races

I spent the next ten years taking as

many mind-altering chemicals as I could

get my hands on

and as a result of that I was kicked out

of three schools I became homeless I

contracted hepatitis C and I ended up in

treatment right after my 23rd birthday I

thought it was going to be a spa this

was in the 80s so I had no idea what

treatment was but I I got to a treatment

center and they said there that if I

wanted to live I was gonna have to be

abstinent which I thought was terrible

deal I wasn't sure but I figured there

was a back way if I had an illness that

was killing me I was going to figure out

a cure for the illness and then I would

be able to use without dying so I

eventually got a PhD in neuroscience and

I've been researching in the field since

then and I haven't solved it and nobody

else has either what we know is that

addiction is characterized by craving

and compulsive use tolerance meaning

that the drug works less and less well

over time and dependence so that when

the drugs go away you feel less good

than normal and those things are are

mediated by about half of it the risk

comes from genetics and the genetic

factors include things like those we've

been talking about so the tendency

toward novelty seeking and risk-taking

is higher in adolescents in adults but

in some adolescents more than others

environmental factors include things

like access and stress and developmental

factors are really important so adverse

experiences early in your life really

prime a person for developing an

addiction as they use to cope but also

just any adolescent exposure really

increases the risk so to talk about what

addiction is I thought I'd give you this

model and start with the idea that we

have a feeling state homeostatic aliy

maintained baseline so if I bumped into

you on the street later and I said how

are you doing and you said I'm doing

fine

that would be your homeostasis yours

might be different than mine but we all

have one this is really actively

maintained by the nervous system and

it's necessary so that we know if

something good or bad happens

for instance if it's your birthday and

you have a great day

you'll feel better than that and that's

how you know you know something

wonderful has happened I don't know if

you've noticed but the day after your

birthday it's usually a little bit of a

letdown

you don't go right back to your middle

baseline that great day you had kind of

comes with the cost and then you return

to baseline the same thing can happen if

an adverse experience occurs so you feel

maybe worried or threatened if that

threat goes away then you feel relaxed

and especially cooled before again

returning to baseline so basically we

start with this homeostatic lis

maintained feeling state that we kind of

move around as good and bad things

happen and that's how we know if good

and bad things happen well some of us

learn that alcohol and other drugs can

cause changes in that feeling state to

make us feel better than our homeostatic

lis maintained baseline but you'll

notice probably that even a drink or two

has a little cost it might be that you

feel not quite normal or a little bit

hungover or you don't sleep as well and

then you come back to your baseline but

we don't have to stop with a drink or

two do we so you could have more than

one drink or maybe throw in a little

weed and that would be better so we can

we can control the delivery of these

things you can only have so many

birthdays right and you can even take

more than just the alcohol in the weed

and get really happy so that seems great

except it's not from the brains

perspective and the brain will adapt to

cause tolerance so that you're not quite

as happy and even eventually enough

tolerance that you're really feeling

basically normal with your drugs that

adaptation is to maintain the baseline

and that also happens when you take the

drugs away is when you really notice it

so if you're now normal with the drugs

when the drugs are gone you're on the

opposite extreme so I thought we could

take an example

when that's kind of close to my heart I

liked all the drugs I could find but I

especially liked smoking marijuana and

this is popular today about 40% of kids

smoked that hasn't changed in the last

few years so much but what has change is

that they're smoking more so many more

smoking daily or frequently and I

thought I'd describe how marijuana works

on the brain and how homeostasis is

maintained so marijuana works THC is the

active ingredient that produces the high

and it activates this endocannabinoid

system that we naturally have so inand

my dand to arachidonic juicer all or 2ag

are neurotransmitters that interact with

all the black spots you're looking at

all over the brain all over the cortex

and areas associated with learning and

memory associated with motivation

associated with reward and when those

chemicals interact they have an effect

obviously our brain wouldn't make these

for no reason I thought I would explain

the effect by telling a story about my

dog my puppy

it was now a hundred pounds but when he

was little he was walking around the

front yard one day and my daughter

dropped a piece of bacon and I could

really practically see his brain light

up he didn't know there was bacon

certainly not living in the grass and I

imagine that his olfactory areas and his

taste sensory cortex his reward areas

may be learning in memory all were

activated with little squirts of an and

amide or two AG to sort of let him know

Wow

bacon this is awesome the same thing

happens for us I don't know what your

bacon is it might be a great line of

poetry or music or some wonderful idea

you have or a good talk but you'll

release these chemicals to let you know

that's something really salient or

relevant is going on

the reason this system is all over the

brain is because we never know what

exactly we're going to find important it

helps us to sort what's important by

sort of highlighting those events or

experience

that are particularly meaningful and

this plays a big role in learning in

memory and it really helps us sort what

we care about and what we don't care

about no THC is a little different isn't

it because it's not sympathize

synthesized and released when we have

great experiences we just smoke it in a

bong or a high potency joint and it goes

all over the brain and it all those

interacts in all those black spots so in

other words everything is bacon which is

a lot of fun I think I loved that you

know everything was so more much more

rich and meaningful and even a tedious

day at work could be interesting of

course the brain doesn't like it this

way because then you can really can't

tell when something important happens so

it compensates and the way it does is

illustrated in this picture of again rat

brains on the left your left is a rat

that has had no THC or tasty like analog

and on the right is a brain all the way

on the right that had a high dose for

about 14 days and I bet that my brain

when I stopped smoking looked a lot like

the one on the right and what it felt

like to me was that nothing was really

interesting nothing was motivating

nothing was really worthwhile time with

my family yeah you know my aspirations

not so important anymore the only way in

fact that I could find anything worth

doing was to be completely stoned this

happens to people who smoke a lot of

weed you can see in the green all the

areas that there's these interaction

sites are lost and regular smokers and

if this is occurring during development

when meaning is so important we're

supposed to be trying new things and

figuring out who we are then the cortex

is organized differently those effects

in blue are probably permanent and they

lead to a kind of a different way of

processing information one important

thing about the way we process

information if we smoke a lot of weed is

that what we used to find

rewarding and pleasurable is no longer

that important so back to our model it's

fun to get high acute with the

occasional use but if you do it

regularly your brain is going to adapt

getting rid of those interaction sites

so that now you're not really high and

when the weed goes away there's a lot of

despair substance abuse is the number

one killer for people under 50 and if we

take addictive drugs on a regular basis

they cause feeling states exactly

opposite to the ones we want to have

when I started smoking weed I loved how

it made everything interesting and fun

by the time I quit smoking nothing was

interesting and nothing was fun thank

you for listening

you