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Transcript
Alcohol and the Adolescent Brain
Ken Winters, Ph.D.
Department of Psychiatry
University of Minnesota
[email protected]
U.S.E.D. Grants to Reduce
Alcohol Abuse Conference
November 18, 2003
Our ex-Governor was
a professional wrestler
Staff are all above average.
Women are strong.
Men are good looking.
U of Minnesota,
Center for Adolescent
Substance Abuse Research
1. Developmental Issues
6. Prevention and
Treatment
2. Brain Functioning
3. Adolescence and
the Brain
5. Youth, Brain
and Alcohol
4. Brain and Alcohol
Are adolescents
more susceptible to
alcohol than adults?
Is addiction a
brain disorder?
1. Developmental Issues
Alcohol Use by Youth
Youth alcohol use occurs on a continuum
Most youth have used some alcohol
7 million
teens binge
drink at least
once a month
Alcohol Use
Trends in prevalence of drugs for 12th graders: 1994 to 2001
Year
30-Day
Alcohol %
1994
50.1
1995
51.3
1996
50.8
1997
52.7
1998
52.0
1999
51.0
2000
50.0
2001
49.8
MTFS, 1975-2001
Alcohol Use Disorders (AUDs)
are Relatively Rare
AUD rates
vary;
3-10%
Most youth
who use do
not meet criteria
for abuse or
dependence
Alcohol Problems
boy AUD rates >
girl AUD rates
Long-Term, Heavy Use of Alcohol
 Significant shrinking of the brain
 50% - 75% show cognitive impairment
 Effects remain even after detoxification &
abstinence
 Alcohol dementia is 2nd-leading cause of adult
dementia
Trends in prevalence of drugs for 12th graders: 1994 to 2001
Year
1994
Daily
Cigarettes %
19.4
1995
21.7
1996
22.2
1997
24.5
1998
22.5
1999
23.1
2000
20.5
2001
19.0
MTFS, 1975-2001
Marijuana: Trends in Perceived Availability,
Perceived Risk, and Use for 12th Graders
100
80
60
Availability
Risk
Use
40
20
0
1975
1977
1979
1981
1983
1985
1987
1989
1991
1993
1995
1997
Availability= Fairly easy or very easy to get
Risk = Great risk of harm in regular use
Use= Once or more, past 30 days
1999
2001
MTFS, 1975-2001
Non-Medical Use of
Prescription Drugs
• The rapid rise in use of club
drugs, methamphetamine, and
oxycodone has put a spotlight on
the non-medical use of
prescription drugs.
• Increase by 11% in 2001 compared
to previous year.
• Exceeds combined use of heroin,
cocaine, crack and hallucinogens.
Comorbid Disorders with AUD
Many predate
onset of AUD
ADHD
> comorbidity,
>AUD
Oppositional
Defiance
Disorder
Depression
Alcohol Use
Disorder
Conduct
Disorder
Gambling
Relapse > if
comorbidity
Anxiety
Medication may
be appropriate
Developmental Phases of
Adolescence
• Individuation
• need to develop personal identity
• Separation
• need to separate from parents
These forces can disrupt our
prevention and treatment efforts
Stages of Change
Prochaska and DiClimente
Maintenance
Action
Action
Preparation
Relapse
Pre-contem.
Precontemplation
Contemplation
Stages of Change for Most Youth?
Contemplation Prep
Pre-contem.
Precontemplation
Working with parents
1. Developmental Issues
2. Brain Functioning
What a Machine!
 100 billion neurons in the brain
 Cortex is 1/8 inch thick like bark
– 80% of it is neurons
 Fastest brain messages = 360
mph
 Over 90 neurochemicals are
involved in transmission of
impulses across neurons
Brain Functioning
 Humans are “wired” with nerve cells
(neurons)
 Neurons group together to form
strands (up to 4 feet long)
 Strands perform specific function
 They extend from brain to spinal cord
Brain Functioning
 Strands are not continuous - they have
small spaces in between
 Spaces are called synapses
 Neurons pass messages through the
synapse with chemicals
 Chemicals are called neurotransmitters
 Drugs affect neurotransmitters
“The 3 pound organ that rules the body is finally giving up its
secrets”
(TIME, August, 2001)
1990’s information explosion
MRI
PET
CAT
These brain imaging techniques produce
windows to observe the effects of
substances on the brain
Imaging Modalities
CT
Anatomic MRI
SPECT
MR Spectroscopy
FDG PET
Ligand PET
fMRI
Diffusion MRI
Your Brain on Alcohol
1-2 Min
3-4
5-6
6-7
7-8
8-9
9-10
10-20
20-30
Your Brain After Drugs
Normal
Alcohol Abuser
Alcoholic
1. Developmental Issues
2. Brain Functioning
3. Adolescence and the
Brain
The Adolescent Brain is Still
Developing
During adolescence, the brain is
undergoing dramatic transformations
In some brain regions, over 50 % of
neuronal connections are lost
Some new connections are formed
Net effect is pruning (a loss of neurons)
Adolescent Brain Changes
These brain changes are
relevant to adolescent
behavior
Prefrontal cortex (PFC) is
pruned; not fully
developed until mid-20’s
Amygdala (and n.a.) show
less pruning and tend to
dominate the PFC
prefrontal
cortex
amygdala
nucleus
accumbens
judgment
reward
system
I like
to use
drugs!
!
PFC
amygdala
NOT decisions
GOOD NEWS!
“hot”
more
likely than “cold”
 planned
thinking
decisions
 impulsiveness
 self-control
 risk-taking
In the presence of stress…
PFC
I hate
school; I am
going to
skip classes
and get
drunk
amygdala
GOOD NEWS!
The pruning of the PFC neurons
produces a more efficient PFC by
young adulthood
I am
planning for
the future
amygdala
PFC
1. Developmental Issues
2. Brain Functioning
3. Adolescence and the
Brain
4. Brain and Alcohol
Is addiction a
brain disorder?
From “Oops” to Dependence
“Oops Phenomenon”
 First use to “FEEL GOOD”
 Some continue to
compulsively use because
of the reinforcing effects
(e.g., to “FEEL NORMAL”)
 Changes occur in the
“reward system” that
promote continued use
Reward System
The reward system is
responsible for seeking
natural rewards that
have survival value
seeking food, water,
sex, and nurturing
Dopamine is this
system’s primary
neurotransmitter
reward
Drugs Hijack the Brain’s
Reward Circuitry
 Continued use of alcohol reduces the
brain’s dopamine production.
 Because dopamine is part of the reward
system, the brain is “fooled” that
alcohol has survival value for the
organism.
 The reward system responds with “drug
seeking behaviors”
 Craving occurs and, eventually,
dependence.
reward
‼
Evidence
 Animal Studies:
 electrodes attached to “Reward Circuit”
 animals press lever to receive stimuli to brain
 they continue until collapse from exhaustion
 Behavioral Genetics Studies:
 heredity plays a role
 identical twins: > chance of becoming alcoholics than fraternal twins
 adoptive children of alcoholics: > chance of becoming alcoholic;
even true when raised by non-alcoholic parents
 further research needed by gender
Human Studies: amygdala has memory of the drug after
discontinuation.
amygdala
not lit up
Front of Brain
amygdala
activated
Back of Brain
Nature Video
Alcohol Video
1. Developmental Issues
2. Brain Functioning
3. Adolescence and the
Brain
5. Youth, Brain
and Alcohol
4. Brain and Alcohol
Are adolescents
more susceptible to
alcohol than adults?
Is addiction a
brain disorder?
Are adolescents more susceptible
to alcohol than adults?
 Adult studies suggest
that the areas of the
adolescent brain that
are remodeled are
sensitive to the
effects of alcohol
prefrontal
cortex
amygdala
nucleus
accumbens
Difficult scientifically and
ethically to study adolescent
sensitivity to alcohol
Are adolescents more susceptible
to alcohol than adults?
 Animal models can be easily used to
explore this issue
 Role of psychosocial factors can not be
studied
Are adolescents more susceptible
to alcohol than adults?
1. Adolescent rats are less sensitive to
effects of intoxication and less sensitive
to the “hangover” that follows use
Are adolescents more susceptible
to alcohol than adults?
2. Adolescent rats are more sensitive
to the social disinhibition induced
by alcohol use
Wanna look
for some cheese
with me?
Sure!
Are adolescents more susceptible
to alcohol than adults?
3. Adolescent drunk rats perform
worse on memory tasks than adult
drunk rats
converts
information
to memory
Ugh?
?
disrupts the hippocampus
brain damage in the PRF
planne
d
thinkin
g
Supporting Human Studies
1. Reduced
Reduced sensitivity
sensitivity to
to
1.
intoxication
intoxication
2. Increased sensitivity to
social disinhibitions
3.
Greater
adverse
effects
3. Greater adverse effects
to cognitive
cognitive functioning
functioning
to
Survey Data Suggest that Adolescents
Are More Sensitive to Alcohol
Monitoring the Future, 2001
100
80
5+ drinks in row, past 2 weeks
60
Been drunk past month
40
26
20
0
14
24
30
32
8
8th Graders
10th Graders
12th Graders
Alcohol’s Effects
(Brown, 2002; Wuethrich, 2001)
 Adolescents with a history of extensive
use….
converts
informatio
n to
memory
Hippocampus (50%)
brain activity during memory tasks
brain activation when shown alcohol images
trigger
for
relapse
Are adolescents more susceptible
to alcohol than adults?
4. Hyperexcitability issue
Are adolescents more susceptible
to alcohol than adults?
4. Hyperexcitability issue

Alcohol relieves hyperexcitability state

Relief is temporary; continued seeking of
alcohol is reinforced


Hyperexcitability is a key characteristic of
conduct disorders, ADHD & other impulsive
behaviors
Found in non-alcoholic relatives - suggests
inheritance of brain wave patterns
ADHD
Sub Use Dis
ODD
Con Dis
Are adolescents more susceptible
to alcohol than adults?
Most certainly YES
1 Reduced sensitivity to intoxication
2 Increased sensitivity to social
disinhibitions
3 Greater adverse effects to cognitive
functioning
4 Medicates “excitability”
Less We Forget:
The Adolescent Brain is Susceptible
I like
to use
drugs!
!
PFC
amygdala
“hot” decisions more
likely than “cold”
decisions
1. Developmental Issues
6. Prevention &
Treatment
5. Youth, Brain
and Alcohol
Key
Concepts
2. Brain Functioning
3. Adolescence and the
Brain
4. Brain and Alcohol
Are adolescents
more susceptible to
alcohol than adults?
Is addiction a
brain disorder?
Implications for Prevention
and Treatment
Prevention
The earlier the better
Educate them about the
susceptibility of the
adolescent brain and
alcohol exposure
Skills training in the
context of competing
“voices” (PFC vs amygdala)
Marijuana: Trends in Perceived Availability,
Perceived Risk, and Use for 12th Graders
100
80
60
Availability
Risk
Use
40
20
0
1975
1977
1979
1981
1983
1985
1987
1989
1991
1993
1995
1997
Availability= Fairly easy or very easy to get
Risk = Great risk of harm in regular use
Use= Once or more, past 30 days
1999
2001
MTFS, 1975-2001
Implications for Treatment
 Psychosocial treatment
 Verbal skills required in therapy
may be compromised
 Behavioral demands of selfcontrol and relapse prevention
may be compromised
 Medications are being
clinically tested to . . .
 Decrease anxiety and depression
associated with initial stages of
recovery
 Decrease desire to drink
 Treat co-existing disorders
NALTREXONE, ACAMPROSATE, SSRI’S
Is
Evidence
Addiction
to aSupport
Brain Disorder?
a “Yes”
Adolescence
is a time
limitedremember…
disorder
When
working with
teenagers,
THANK YOU!
[email protected]
extras
References
 Leshner A. Oops. How casual drug use leads to addiction. National
Institute on Drug Abuse web site:
www.drugabuse.gov/Published_Articles/Oops.html
September, 2000.
 National Institute on Alcohol Abuse and Alcoholism. Imaging and
Alcoholism: A Window on the Brain.
Alcohol Alert No. 47, April 2000.
 National Institute on Alcohol Abuse and Alcoholism. Tenth Special
Report to the U.S. Congress on Alcohol and Health, NIH Pub. No. 001583, 2000.
 National Institute on drug Abuse. Principles of drug addiction
treatment: A research-based guide.
No. 99-4180, 1999.
From Discover vol. 22, No. 3, March 2001
Meta analysis by Bernice Wuethrich






7 million youths between ages 12 and 20 binge drink at least
once a month
Teen drinkers most susceptible to damage in the
hippocampus and the prefrontal cortex
The hippocampus is 10% smaller in teens who use alcohol
Alcohol blocks long term potentiation in adolescent brain
tissue; the production of glutamate which is responsible for
memory formation
The impact on the developing brain continues through the
early twenties
It is suspected that the physical impact of withdrawal – cell
death and increase in number and sensitivity of hyperactive
receptors – creates the brain damage.
Brown, 2002; Wuethrich, 2001
American Medical Association, 2002
Sandra Brown, Ph.D.,
San Diego, Veterans Affairs Medical Center
 Drinking at a young age can impair memory
development and the ability to learn
permanently
 Research matched 56 adolescent drinkers with
56 non-drinkers
 When given standardized test the drinkers
scored worse in vocabulary, general
information, memory and memory retrieval
 Problems continued through years of follow-up