Transcript Kids and Drugs - Maple Heights City Schools

BRAIN RESEARCH
THE EFFECTS OF ALCOHOL ON THE ADOLESCENT BRAIN
Ken Winters, Ph.D.
Department of Psychiatry
University of Minnesota
[email protected]
CSAP’s Western CAPT
Audio Teleconference
March 18, 2004
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
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
1. Developmental Issues
2. 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
amygdala
Prefrontal cortex (PFC) is
pruned; not fully
developed until mid-20’s
nucleus
accumbens
judgment
Amygdala (and n.a.) show
less pruning and tend to
dominate the PFC
reward
system
I like
to use
drugs!
!
PFC
amygdala
This imbalance leads to...
 planned thinking
 impulsiveness
 self-control
 risk-taking
more “hot” talking, less “cool” talking
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. Adolescence and the
Brain
3. Brain and Alcohol
Is addiction a
brain disorder?
“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
 Immediate effect of drug use is an increase
in dopamine
 Continued use of drugs reduces the brain’s
dopamine production.
 Because dopamine is part of the reward
system, the brain is “fooled” that the drug
has survival value for the organism.
 The reward system responds with “drug
seeking behaviors”
 Craving occurs and, eventually, dependence.
reward
1. Developmental Issues
2. Adolescence and the
Brain
4. Youth, Brain
and Alcohol
3. Brain and Alcohol
Are adolescents
more susceptible to
alcohol than adults?
Is addiction a
brain disorder?
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?
Most certainly YES
1 Reduced sensitivity to intoxication
2 Increased sensitivity to social
pressure
3 Greater adverse effects to cognitive
functioning
4 Medicates “excitability”