Download Addiction and the Brain

Addiction and the Brain
The Least You Need To Know:
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Neurotransmitters (define)
reward pathway (define)
Old brain vs. New brain (general)
down-regulation (describe)
oops phenomenon (general)
drug use continuum (when addicted?)
Recap:
Choice or
Disease?
Substance Abuse: The Nation’s
Number One Health Problem
Robert Wood Johnson Foundation, 2006
“Drug Addiction is a Brain
Disease”
Alan Leshner, PhD
National Institute of Drug Abuse
Former Director
The Beginning of Brain Research
Trepanized skulls
1848
Neurotransmitters: Chemical Messengers
Intro
The Big Two:
• Serotonin: mood, emotion, sleep
and appetite
• Dopamine: pleasure and elation
Many drugs work
by mimicking a
naturally
occurring
neurotransmitter
in the body.
Release of Dopamine in the Rat Nucleus
Accumbens: Acute Administration
Dopamine (% Change)
300
250
Footshock
Sucrose
Cocaine
Nicotine
Alcohol
200
150
100
50
0
60
120
180
Time (min)
Kalivas, P. 2002
240
OLD BRAIN VS. NEW BRAIN
Transition to Addiction
Good
to
Bad
• Increased Energy
“It sustains
and refreshes both body and brain...... in
the same space of time more than double
the amount of work could be
undergone...” Sears, Roebuck, and Co.
Consumers Guide, 1900
• Euphoria
“.....exhilarating and
lasting euphoria.... You perceive increase
in self-control and possess more vitality
and capacity for work.” Sigmund Freud,
1884
Replace Natural Reward
"A coke
shot...it's like...
Craving
“I found I was taking money
meant to buy presents for my children.”
Paranoia
“He thought he was being
forcibly electrocuted and could see electric
wires leading to his body.”
Oops Phenomenon
• First use to Feel Good
• Some continue to compulsively use
because of the reinforcing effects
– To Feel Normal
• Changes occur in the reward system
that promote continued use.
Something truly scary….?
If you remember one thing about drugs….
National Institute on Drug Abuse, 2002; Monkey Brain
What is Down-Regulation?
National Institute on Drug Abuse, 2000
PET/fMRI of Cocaine Craving
Childress et al., 1999; Am.J.Psychiat
Relapse or
Recidivism
Why 8-9
out of 10?
Or around
80-90%...
Go back to using!
‘Down’ in the Dumps
Down-Regulation
• Immediate effect of drug use is an
increase in dopamine or NT’s
• Continued use of drugs reduces the brain’s
dopamine (or NT) 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”
Imagine……
DRUG USE CONTINUUM
Abstinence
Experimentation
Drug Use
Drug
Abuse
Addiction
The face of addiction:
http://www.youtube.com/
watch?v=02ngAsHRg4A
Essential Questions
• So…is addiction a Choice or
disease?
• How are depression and drug use
related?
• How does someone become an
‘addict?’