Transcript SI Addiction2

Percentage Probability of Becoming Addicted to Alcohol
Based on When the Individual Started Drinking
50
45
40
35
30
25
20
15
10
5
0
<13
14
15
16
17
18
Age Began Drinking
Source: Hingson, R.W. , Heeren T., and Winter, M.R., “Age of Drinking Onset and
Alcohol Dependence,” Archives of Pediatrics and Adolescent Medicine,” 2006.
19
20
21
Brain Regions and Functions
PLEASURE/REWARD
The Frontal Lobes
• Executive Functions
•
•
•
•
•
Abstraction
Sequencing
Prioritization
Planning
Judgment
• Frontalization from
Amygdala of
Identifying Emotion
Neurotransmission
Chemical Neurotransmission
in the Brain’s Pleasure Circuit
Axon of transmitting
Nerve Cell
Dendrite
of
receiver
Nerve
Cell
Pleasure
Axon of
transmitting
Nerve Cell
Regulation
seratonin
seratonin
receptor
Dendrite of receiver Nerve Cell
Drugs of Abuse Increase Brain
Dopamine and/or Serotonin
Dopamine drugs
Serotonin Drugs
• Heroin, Oxycontin, Vicodin,
mimic dopamine
• Amphetamines, Ecstasy
cause excessive serotonin
release
• Alcohol causes excessive
dopamine release
• Nicotine prevents
dopamine breakdown
• Cocaine prevents
Serotonin Re-uptake
(incidentally so do antidepressants such as Zoloft,
Paxol, etc.)
RESPONSE #1
• Brain builds more receptors to catch excess
dopamine/serotonin
= serotonin
THE BRAIN RESPONDS
BRAIN BLOCKS OFF AVAILABLE
RECEPTORS IN SELF DEFENSE
Pleasure
Axon of
transmitting
Nerve Cell
Regulation
seratonin
seratonin
receptor
Dendrite of receiver Nerve Cell
Dr. Andrew Weil (M.D.)
The Pleasure of Altering Consciousness
"the desire to alter consciousness
periodically is an (instinctive), normal
drive…." with drugs only being one of
many ways to satisfy this need.
~ The Natural Mind: From Chocolate to Morphine
Dr. Weil’s Definition of a Bad
Relationship with a Drug
• Ignorance of what the drug does to your
body
• Loss of the desired effect despite increasing
frequency of use
• Difficulty separating from the drug
• Impairment of health or impairment of
social functioning
amphetamines
ecstasy
LSD
PET Scans
(Positron Emission Tomography)
Color reflects metabolic activity in the brain
RED is hot
BLUE is not
Immediate effects of
Cocaine in the brain
Cocaine
acutely
activates
the brain
Scan from Brookhaven NLCIN
CHRONICALLY (long term)
Cocaine reduces brain activity
Normal Brain
User’s Brain
Scans from Brookhaven NLCIN
Normal resting brain activity
Cocaine abuser’s resting brain activity
Scans from Brookhaven NLCIN
Normal resting brain activity
Marijuana user’s resting brain activity
Scans from Brookhaven NLCIN
Serotonin Activity Shuts Down
in Ecstasy Users
Non-user’s brain
Ecstasy user’s brain
From The National Institute for Drug Abuse Prevention
Addiction
is the creation of a negative state
Initially the drug is used to feel high...
...over time, the drug is necessary to just feel normal
(bring brain activity to normal levels)
The developing brain is more vulnerable
to addictive drugs
CEREBRAL BLOOD FLOW
ANNUAL INCREMENTS
3-4
150
5-6
8-9
Ml/min
12-14
15-17
- 150
2
4
6
8
10
12
AGE (years)
14
16
18
Increased blood flow precedes the brain’s growth spurts
Brain and Development 1999;21:535
THE PREFRONTAL CORTEX
AND HIPPOCAMPUS
GROW FASTEST IN ADOLESCENCE
PREFRONTAL
CORTEX
reason,
judgement
PLEASURE/REWARD
HIPPOCAMPUS
memory
Frontal Lobe Brain Dysfunction
in a Young Drinker
Back of
head
Front
of head
20 yr. old nondrinker
20 yr. old regular drinker
Alcoholism: Clinical and Experimental Research, 2001;25:236
Alcohol Shrinks the Brain
Alcoholic
Normal (control)
From The National Institute for Alcohol and Alcoholism Research
Hippocampal Volume Shrinks
with Adolescent Alcohol Use
Non-drinking adolescent
Adolescent binge drinker
American Journal of Psychiatry, 2000;157:737
“New research indicates that
teenagers who drink too much
may lose as much as
10% of their brainpower-”
What does that 10% mean to you?
Discover, Vol 22, March 2001
• The brain keeps growing, developing new neurons, and setting up
circuits into the 20’s
• Substance abuse in adolescence is more likely to lead to addiction
• 1 in 3 adolescents who smoke,
1 in 4 adolescents who drink,
1 in 5 adolescents who use marijuana…
… will become dependent on the drug
• Even if one escapes addiction, drugs put the brain at risk for
chronic changes that can affect function
• Drug-induced brain damage is cumulative and may not be reversible
The media notoriously paints only half
the picture of substance abuse
Scene from
Dawson’s Creek
Do the Math
Media glorification/advertisement
+ Immediate consequences rarely seem severe
+ Pressures to use
+ Denial psychology/cognitive dissonance
_____________________________________
= Easier to use than not to use?
This is your brain
This is your brain on drugs
NIDA Drug Prevention Campaign
Neurotoxic Effects of Stimulant Addictive Drugs
Nicotine, Cocaine, Ecstasy, Amphetamines
UCLA Brain Research Institute
Neuropharmacology 2000;39:2792