Download Presentation for workshop 4

THE ADOLESCENT BRAIN AND
DRUGS
Michael Brunner, Ph.D., LP, ABPP
Mayo Clinic Health System – Fountain Centers
[email protected]
Fountain Centers Website:
http://mayoclinichealthsystem.org/locations/albert-lea/fountain-centers
Objectives
• Describe normative adolescent brain
development and three reasons adolescents are
prone to engaging in risky behaviors, such as use
of alcohol and other drugs.
• Identify four risk factors associated with
adolescent substance use problems and
addiction.
• Name at least three skills that will lead to
productive discussions with teens about alcohol
and other drugs.
What Teens Need
• Independence/autonomy/freedom (with
limits)
• Structure, clearly established
expectations
• Support/Love
• Commitment from adults
• Connection
• Clear communication
Images (above and left) from:
http://www.utahsafetycouncil.org/AA25/parents.asp
Image from: http://www.ramthilakceo.com/2012/02/beingmodern-indian-parent.html
Image from: http://becuo.com/hispanic-mom
Drug Use in Adolescence
Alcohol
Marijuana
Cigarettes
All Other
Illicit Drugs
Use In Last 30 Days Any Lifetime Use
21.8
45.2
14.0
30.0
7.0
21.1
5.1
16.1
Percent 8th, 10th and 12th Grades Combined
Monitoring the Future (2015)
Rates steady over the last decade +.
Not much in the way of racial differences.
Increasing use with age.
Rates steady over the last decade +.
Not much in the way of racial differences.
Increasing use with age.
Rates mostly declining over the last decade +., although steady for black teens.
Black teens least likely to use drugs other than marijuana.
Increasing use with age.
Rates declining over the last decade +.
Black teens use less alcohol.
Increasing use with age.
Rates dramatically declining over the last decade +.
White teens most likely to smoke cigarettes.
Slight increase in use with age.
Drug Use in Adolescence
• Main Finding From 2015 Monitoring the
Future Study:
• The use of alcohol and cigarettes reached their
lowest levels since the study began in 1975.
• The use of several other illicit drugs including
MDMA (ecstasy), heroin, amphetamines, and
synthetic marijuana also declined in 2015.
• Marijuana use remained comparable to 2014. Use
has remained steady over the last 20 years.
Cigarette Use and Attitudes
Use declines . . .
Monitoring the Future (2015)
as perceived risk and
disapproval increase.
Marijuana Use and Attitudes
Use has remained even as perceived risk and
steady. . .
disapproval have declined.
Monitoring the Future (2015)
DRUG USE CONSEQUENCES
Marijuana Consequences
• Dose-response relationship:
• The more a person uses the worse the outcomes.
• Compared to those who never used marijuana,
those who used daily before age 17 have:
• A reduced likelihood of completing high school and
getting a degree.
• Increased odds (18x) of cannabis dependence.
• An increased likelihood (8x) of using other drugs.
• An increased risk (7x) of making a suicide attempt.
Silens et al (2014)
Marijuana Consequences
• Dose-response relationship:
• The more a person uses the worse the outcomes.
• Compared to those who never used marijuana,
those who used daily before age 17 have:
• A reduced likelihood of completing high school and
getting a degree.
• Increased odds (18x) of cannabis dependence.
• An increased likelihood (8x) of using other drugs.
• An increased risk (7x) of making a suicide attempt.
Silens et al (2014)
Marijuana Effects on the Brain
• Impairs decision making, planning,
organization, problem-solving, memory, motor
coordination, reaction time, and learning.1
• Persistent use shows an average decline of 8 IQ
points.2
• Uncertain recovery after discontinuation.
• Degree of impairment is related to age of
onset3, recency and frequency of use4, and
duration of use.2
1
Chang et al (2006)
3
Jacobus et al (2015): Gruber et al (2014)
2
Meier et al (2012)
4
Crane, Schuster, & Gonzalez (2013): Lisdahl & Price (2012)
Marijuana Association with Psychosis
• Smoking marijuana at an early age
increases a person’s risk of
developing a mental illness such as
schizophrenia.1
• Heavy marijuana use increases the risk of psychosis (a
symptom of schizophrenia) by up to 700% compared to
those who do not smoke it.2
• People with certain genes are at a much greater risk for
psychosis if they smoke marijuana.3
1
2
3
Andreasson et al (1987)
http://www.schizophrenia.com/prevention/streetdrugs.html
Caspi et al (2005)
Alcohol Consequences
• The earlier the age at which a youth takes their
first drink of alcohol, the greater the risk of alcohol
use problems.1
• Problem drinking in late adolescence is associated
with adverse outcomes in adulthood2 such as:
•
•
•
•
General health problems,
Lower life satisfaction,
Truncated education, and
Financial difficulties.
1
Blomeyer et al (2013)
2
Rose et al (2014)
Image from: http://vedicviewsworldnews.blogspot.com/2010/06/te
en-girls-use-alcohol-drugs-tocope.html
Alcohol Effects on the Brain
• Teens with alcohol use disorders found to have
neurocognitive impairments including problems with
memory, visuospatial performance, sustained attention,
retrieval, information processing, language, and executive
functioning.1
• The brains of heavy drinking adolescents react to alcohol
cues compared to those who do not drink. This heightened
reactivity disappears after one month of abstinence.2
• Days of alcohol use was associated with adverse changes
observed 1.5 years later – the damage appears to endure.3
• Alcohol use disrupts the transition into early adulthood with
those using alcohol having more negative outcomes such as
poorer health, truncated education, financial problems, and
increased substance use problems.4
1
Jacobus & Tapert (2014)
3
Bava et al (2013)
2
Brumback et al (2015)
4
Rose et al (2014)
STRENGTH OF EVIDENCE THAT PROBLEM DRUG USE*
DURING ADOLESCENCE AFFECTS
BRAIN FUNCTIONING
1
2
3
4
5
6
7
8
9
10
9
10
BRAIN STRUCTURE
1
2
3
4
5
6
7
*Frequent, repeated use over an extended period of time
8
STRENGTH OF EVIDENCE THAT BRAIN CHANGES DUE TO
PROBLEM DRUG USE* ARE HARMFUL
1
2
3
4
5
6
7
8
9
10
STRENGTH OF EVIDENCE THAT CHANGES DUE TO PROBLEM
DRUG USE* DURING ADOLESCENCE ARE LONGLASTING
1
2
3
4
5
6
7
*Frequent, repeated use over an extended period of time
8
9
10
ADOLESCENCE: ADDICTION RISK
Developmental Factors and Addiction
• Adolescents and young adults exhibit
higher rates of experimental use and
substance use disorders than adults.
• Addictive disorders identified in adults
most commonly have their onset in
adolescence or young adulthood.
• Earlier onset of substance use predicts
greater addiction severity and
likelihood of using multiple substances.
Chambers, Taylor, & Potenza (2003)
Most Drug Use Begins in Adolescence
NIDA (2008) - http://www.drugabuse.gov/publications/addiction-science
Adolescents are at Greatest Risk for a
Diagnosis of Substance Dependence
Slide from NIDA (2008): http://www.drugabuse.gov/publications/addictionscience. Source cited: National Epidemiologic Survey on Alcohol and Related
Conditions (2003)
Initiating Substance Use in Adolescence Sets
the Stage for Adult Drug Use Problems
Ninety percent of all Americans with a substance use
disorder began using alcohol, tobacco, or other
illicit substances before age 18.
One in four Americans who start using any substance
of abuse prior to age 18 will go on to have a
substance use disorder in adulthood compared to
1 in 25 who started using after the age of 21.
If you initiate
substance use
Prior to 18
compared to
18 or older
The National Center on Addiction and Substance Abuse at Columbia University (June 2011)
You have a 6-fold
greater risk of
having a severe
problem.
Marijuana Example
If you ever use
marijuana, your
risk of becoming
addicted is:
9%
1
Lopez-Quintero wt al (2011)
2
Hall et al (2009)
See also Volkow et al (2014)
If you start using
marijuana as a teen,
your risk of becoming
addicted is:
17%
2
1
What is Addiction?
• A chronic, relapsing brain disease that is
characterized by compulsive drug seeking and
use, despite harmful consequences.1
• It is considered a brain disease because drugs
change the brain. They change its structure
and how it works.1
• There is damage – a physical defect – to the
brain and how it functions. 2
1
https://www.drugabuse.gov/publications/media-guide/science-drug-abuse-addiction-basics
2
See, for example, http://www.instituteforaddictionstudy.com/PDF/Addiction%20Q%20%26%20A.pdf
Addiction-Related Brain Structures/Regions
Healthy Brain:
Primary Regions/Structures Associated with
each of the Circuits are in
NA – Reward +
Motivation
AMY – Stress
DS - Habit
DS
PFC – Planning
PFC
NA
AMY
Brain Structures and Function Affected By
Addiction
Stress
Over
Activation
Habit
Adaptive
Zone
Under
Activation
Decision Making
Problem Use
Onset
Reward
Use
Problem
Use
Disorder
Disease
Addiction and Functional Control
Frontal to Striatal
Deliberative to Automatic
processing
Ventral to Dorsal
Reward + Motivation to
Habit
Substance Use Disorders and Other
Psychiatric Conditions: A Continuum
• Psychiatric conditions affect the brain.
• Problems are revealed by the
emergence of symptoms.
• The degree of impairment suggests the extent of
progression from problem to disorder to disease.
A Continuum
Healthy
Problem
Disorder
PET Scan
http://pubs.niaaa.nih.gov/publications/aa63/aa63.htm
Disease
Risk Factors Associated with Addiction
Characteristic
Example
“Addiction-loaded” phenotype
Trait impulsivity
Exposure to social toxins
Adverse Childhood Experiences,
Poverty
Life circumstances
Chronic stress, subordinate social
status, social isolation
In a drug use-supporting environment
Low parental involvement, ”using”
parents/peers, culture that
accepts/promotes drug use
Use of more addictive drugs
Heroin, tobacco, methamphetamine
Using regularly and in a manner that
results in rapid euphoria
Daily use, inhalation
Exposed early in life or during critical
developmental period
Gestation; Pre-adolescence
Risk Factors Associated with Addiction
Characteristic
Example
An
Addiction “Frankenstein”
“Addiction-loaded” phenotype
Trait impulsivity
Exposure to social toxins
Adverse Childhood Experiences,
Poverty
Life circumstances
Chronic stress, subordinate social
status, social isolation
In a drug use-supporting environment
Low parental involvement, ”using”
parents/peers, culture that
accepts/promotes drug use
Use of more addictive drugs
Heroin, tobacco, methamphetamine
Using regularly and in a manner that
results in rapid euphoria
Daily use, inhalation
Exposed early in life or during critical
developmental period
Gestation; Pre-adolescence
Biology Shaped By Experience
Image from: http://the-sieve.com/tag/epigenetics/
Addiction Considerations
• Acquisition of the disease of addiction
is a process from:
• Use to Problem Use to Disorder to Disease
• Not all who use alcohol or other drugs have a
disorder or are addicted.
• Therefore, assess extent to which use is a problem to
determine what interventions, if any, are warranted.
• Addiction risk is determined by multiple
factors including:
• Age, gender, extent of use, route of administration, drug(s)
used, genetic vulnerabilities, life events (e.g., adverse
childhood experiences, acute stressors), environmental
circumstances (SES, social status, isolation)
Addiction and Riptides
Image from: http://www.wikihow.com/Survive-a-Riptide
ADOLESCENT BRAIN DEVELOPMENT
Neural Plasticity
• Adolescence is a period of
tremendous neural plasticity - normal development influenced by
environmental factors reshape
brain circuits.
• The neurotransmitter dopamine
(DA) affects learning, narrowing or
focusing attention and motivation.
• Experiences that evoke DA during
adolescence reshape the brain.
Neural Development During
Adolescence
The two brain regions that are
particularly relevant are:
The Prefrontal Cortex (PFC),
known to be important for
cognitive control.
The Striatum, critical in
detecting and learning about
novel and rewarding cues.
Neurons and Synapses
Image from:
https://www.nia.nih.gov/alzheimers/features/findingsmemory-research-continue-fascinate
Image from: http://www.drugabuse.gov/publications/teaching-packets/neurobiologydrug-addiction/section-i-introduction-to-brain/6-impulse-flow
Image from: http://www.oocities.org/dtmcbride/science/biology/neuro_anatomy.html
Pruning
• “Pruning” is a process that leads to a
reduction in nerve cells in the brain.
• It is a normal process of neurological
development for mammals and occurs
more dramatically in adolescence than
any other time of life.*
• The neural structure is reshaped by
reducing the overall number of neurons
and synapses. This leads to more
efficient neural connections.
• Neurological activity determines which
circuits are pruned.
* Feinberg & Campbell (2012)
Image from:
http://englishinprague.blogspot.com/2011/08/langu
age-and-nationality.html
Myelination
• Neurological activity also
determines which circuits are
strengthened.
• Circuits that are strengthened are
myelinated. These fibers are
referred to as white matter.
• Repeated drug use during
adolescence likely drives
functional and structural changes,
“locking in” patterned drug using
behaviors.
Image from:
http://blackheartletterpress.tumblr.com/post/131687530
65/letterpress-use-it-or-lose-it-bookmarks-hurry-up
Image from: multiple-sclerosis-research.blogspot.com/
* Feinberg & Campbell (2012)
Neural Development in Adolescence
Gray matter declines during adolescence.
This is referred to as “pruning.”
Synaptic pruning – elimination – of
inefficient neuronal connections takes
place.
White matter increases during
adolescence. White matter is wrapped in
a sheath of myelin.
Myelination promotes efficient neuronal
communication.
Brain Maturation Ages 5 to 20. Red indicates more gray matter, blue less gray matter. Gray matter
wanes in a back to front wave as the brain matures and neural connections are pruned. Areas
performing more basic functions mature earlier; areas for higher-order functions (emotion, selfcontrol) mature later. The pre-frontal cortex, which handles reasoning and other "executive"
functions, emerged late in evolution, and is among the last to mature.
Gogtay et al.(2004)
Neural Development:
Time Lapse 4-21 Years of Age
Age in
Years
4
8
Movie from: http://www.youtube.com/watch?v=LT7elnCz6SM
1
Giedd et al (2006)
12
16
21
Age in
Years
Use It or Lose It
Neurons that
fire together,
wire together.
Reward Sensitivity and Executive Control
Development
Children
Striatum
PFC
Adolescents
PFC
Striatum
Striatum
Prefrontal Cortex
Age
Reward sensitivity: Emerges in childhood,
strengthens during adolescence, and then
diminishes in adulthood.
Decision-making and impulse control
abilities emerge in a linear fashion, being
weaker during the early years increasing in
strength in adulthood.
Casey & Jones (2010)
Adults
PFC
Striatum
Impulse Control and Sensation Seeking
Casey & Jones (2010) citing Steinberg et al (2008)
Impulse Control and Sensation Seeking
Smaller, B. New Yorker, 2006
Casey & Jones (2010) citing Steinberg et al (2008)
The Role and Function of Dopamine (DA)
1. Orienting to the reward.
2. Motivating to obtain reward
3. Shaping future behavior to get the reward again.
Maturation of the Reward Circuit
• Adolescents are more motivated to engage
in high-reward behavior because their
reward circuit is hypersensitive – they
experience more DA release – compared to
adults.
• DA levels increase in the reward center (3045% greater than adults) and PFC during
adolescence.
• Males have approximately 4.6 times more
production and elimination of DA in the
reward center compared to females. A
similar pattern is found in the PFC.
• One-third to one-half or more of DA
receptors in the reward center of juveniles
are lost by adulthood.
Galvan (2010)
See also: Jacobus et al (2015)
Maturation of the Reward Circuit
• Adolescents are more motivated to engage
in high-reward behavior because their
reward circuit is hypersensitive – they
experience more DA release – compared to
adults.
• DA levels increase in the reward center (3045% greater than adults) and PFC during
adolescence.
• Males have approximately 4.6 times more
production and elimination of DA in the
reward center compared to females. A
similar pattern is found in the PFC.
• One-third to one-half or more of DA
receptors in the reward center of juveniles
are lost by adulthood.
Galvan (2010)
See also: Jacobus et al (2015)
STRENGTH OF EVIDENCE THAT ADOLESCENCE IS A
TIME OF IMPORTANT BRAIN DEVELOPMENT
1
2
3
4
5
6
7
8
9
10
STRENGTH OF EVIDENCE THAT ADOLESCENTS WITH
DRUG USE PROBLEMS ALTER NORMATIVE BRAIN
DEVELOPMENT
1
2
3
4
5
6
7
8
9
10
STRENGTH OF EVIDENCE THAT SEVERE DRUG USE DURING
ADOLESCENCE INCREASES THE RISK FOR ADDICTION LATER
IN LIFE
1
2
3
4
5
6
7
8
9
10
Section Summary
• Adolescence is the “critical period” for learning how to effectively
modulate reward/risk taking.
• Neural plasticity and pruning define this process.
Image from: https://dana.org/Cerebrum/Default.aspx?id=39481
• If this normal developmental process is disrupted by exposure to
toxins – drugs – the damage to neural circuitry can be significant.
• This process – development impacted by exposure to environmental
toxins – could account for the increased risk for substance use
problems and addiction when drug use is initiated during
adolescence.
Emerging Research
EFFECTS OF DRUGS ON THE
DEVELOPING BRAIN
Marijuana and the Developing Brain
• Research on the effects of marijuana on the
developing brain is in the early stages.
• Results are at odds.
• Some studies find loss of gray matter in areas
responsible for reward and impulse control.1
Others find increases in gray matter.2 Others find
no differences.3
• Some studies find increased white matter
connections.1 Others find impairments in white
matter tracts.4
1
Filbey et al. (2014)
3
Weiland et al. (2015)
2
Gilman et al (2014)
4
Bava et al (2009); Gruber et al (2010 )
Marijuana and the Developing Brain
• Research on the effects of marijuana on the
developing brain is in the early stages.
• Results are at odds.
• Some studies find loss of gray matter in areas
responsible for reward and impulse control.1
Others find increases in gray matter.2 Others find
no differences.3
• Some studies find increased white matter
connections.1 Others find impairments in white
matter tracts.4
1
Filbey et al. (2014)
3
Weiland et al. (2015)
2
Gilman et al (2014)
4
Bava et al (2009); Gruber et al (2010 )
Research: Marijuana and the
Developing Brain
• Chronic marijuana users compared to
nonsmokers demonstrated less white matter
integrity in brain regions critical for planning,
decision making, and impulse control.
• The earlier the age of onset of marijuana
smoking, the greater the impact on the white
matter integrity.
• Marijuana users demonstrated more
problems with impulsivity which was
associated with white matter integrity.
Gruber et al. (2010)
Filbey et al. (2015) found that early adolescent marijuana use disrupted the
normal pruning process
Research: Marijuana and the
Developing Brain
• Chronic marijuana users compared to
nonsmokers
demonstrated less white matter
A
Aplanning,
integrity in brain regions critical for
decision making, and impulse control.
• The earlier the age of onset of marijuana
smoking, the greater the impact on the white
matter integrity.
B
• Marijuana users
demonstrated
more
B
Less efficient
problems with impulsivity
which– slower
was& more diffuse –
communication between brain regions
associated with white matterwith
integrity.
marijuana use.
Efficient – faster & more direct –
Gruber et al. (2010)
communication
between brain
Filbey et al. (2015) found that early adolescent marijuana use disrupted the
regions
without
marijuana use.
normal pruning
process
Alcohol and the Developing Brain –
Gray Matter
• Compared to non-drinking adolescents, those
with episodes of heavy drinking had:
• Faster declining volumes of gray matter.
• In terms of gray matter loss this could mean:
• Accelerated but non-beneficial pruning.
• Premature decline such as that seen in adult
alcoholics.
Squeglia et al., 2015
See also: Jacobus et al , 2015
Alcohol and the Developing Brain –
Gray Matter
• Compared to non-drinking adolescents, those
with episodes of heavy drinking had:
• Faster declining volumes of gray matter.
• In terms of gray matter loss this could mean:
• Accelerated but non-beneficial pruning.
• Premature decline such as that seen in adult
alcoholics.
Absence of early alcohol exposure =
appropriate degree of gray matter
pruning - the brain remains healthy.
Squeglia et al (2015)
See also: Jacobus et al (2015)
Early, heavy alcohol exposure
results in excessive gray
matter pruning.
Alcohol and the Developing Brain –
Matter
• Compared to non-drinking adolescents, those
with episodes of heavy drinking had:
• Smaller increases in white matter (myelinated
fibers)
• Reduced white matter growth in heavy drinking
adolescents is a widespread effect.1
1
Squeglia et al (2015)
See also: Jacobus et al (2015); Bava et al (2013)
Alcohol and the Developing Brain –
Matter
• Compared to non-drinking adolescents, those
with episodes of heavy drinking had:
• Smaller increases in white matter (myelinated
fibers)
• Reduced white matter growth in heavy drinking
adolescents is a widespread effect.1
Absence of early alcohol exposure =
appropriate white matter growth.
1
Squeglia et al (2015)
See also: Jacobus et al (2015); Bava et al (2013)
Early alcohol exposure = decreased
white matter growth and connection.
Alcohol and the Developing Brain –
Matter
• Compared to non-drinking adolescents, those
with episodes of heavy drinking had:
• Smaller increases in white matter (myelinated
fibers)
• Reduced white matter growth in heavy drinking
adolescents is a widespread effect.1
• Poorer white matter integrity is observed in
teens with heavy alcohol use.2
1
Squeglia et al (2015)
See also: Jacobus et al (2015); Bava et al (2013)
2
Jacobus & Tapert (2013, 2015)
Alcohol and the Developing Brain –
Matter
• Compared to non-drinking adolescents, those
A of heavy drinking had:
with episodes
A
• Smaller increases in white matter (myelinated
fibers)
• Reduced white matter growth in heavy drinking
adolescents is a widespread effect.
• Poorer white matter integrity is observed
in
B
B
2
teens with heavy alcoholLess
use.
efficient – slower & more diffuse –
Squeglia et al–(2015)
Efficient
faster & more direct –
See also: Jacobus et al (2015)
communication
between brain
Jacobus & Tapert (2013, 2015)
regions without alcohol use.
1
2
communication between brain regions
with alcohol use.
Altering Gene Expression
No Alcohol
• Alcohol use changed how
genes were expressed in the
emotional area of the brain
which changed the
structure of the brain.
Used Alcohol
• Alcohol use in adolescence is associated with anxietylike behaviors during adolescence which persist into
adulthood and are associated with increased alcohol
consumption.
• This does not occur when alcohol use is initiated in
adulthood.
Pandey et al. (2013)
THE LIKELIHOOD THAT DIFFERENT DRUGS AFFECT
BRAIN DEVELOPMENT IN A SIMILAR MANNER
1
2
3
4
5
6
7
8
9
10
CERTAINTY ABOUT HOW NORMAL BRAIN DEVELOPMENT
IS ALTERED BY SEVERE DRUG USE DURING ADOLESCENCE
1
2
3
4
5
6
7
8
9
10
TALKING DRUGS TO ADOLESCENTS
1. Talk about drugs
with kids.
2. Provide accurate
information.
3. Model behaviors
you want teens
to adopt.
Chassin, Flora, & King (2004); Sieving et al. (2000); Van den Zwaluw (2008)
4. Be realistic.
5. Support
autonomy.
6. Set expectations.
7. Communicate
within the context
of the relationship.
1. Argue or debate.
2. Tolerate use.
Ennett et al. (2016); Jackson et al. (2014); Kaynak et al. (2014);
Andrews et al. (1993); Mares et al. (2011); Sieving et al. (2000)
3. Lose it
emotionally.
4. Provide
information
without getting
permission first.
5. Catastrophize.
6. Reject.
Adolescence Summary
• Adolescence is a crucial time for either avoiding or
developing an addiction.
• Experiencing reward more powerfully and not having the
PFC fully on-line during adolescence are factors
predisposing to addiction.
• Brain development – which involves myelination and
pruning – appears to establish the neural tracts which
locks in addiction at this time of development.
• Talk with teens about drugs and drug use.