addiction and the brain. the least you need to know: neurotransmitters (define) reward pathway...
TRANSCRIPT
Addiction and the Brain
The Least You Need To Know:
• 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?
The costs of substance abuse in the United
States, economically and physically, are
staggering. Alcohol is the most economically
costly at $166.5 billion, followed by smoking at
$138 billion and drug abuse at $110 billion, the
report said. Furthermore, of the more than 2
million deaths each year in the United States, one
in four is attributable to alcohol, tobacco and
illicit drug use.
Substance Abuse: The Nation’s Number One Health Problem
Robert Wood Johnson Foundation, 2006
“Drug Addiction is a Brain Disease”
Alan Leshner, PhDNational Institute of Drug Abuse
Former Director
The Beginning of Brain Research
Trepanized skulls
1848
Neurotransmitters: Chemical Messengers
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
200
250
300
50
100
150
Do
pam
ine
(% C
han
ge)
0 60 120 180 240
Time (min)
Cocaine
FootshockSucrose
NicotineAlcohol
Kalivas, P. 2002
OLD BRAIN VS. NEW BRAIN
• 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.”
Transition to AddictionGood to Bad
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 CravingChildress 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……
Abstinence
DRUG USE CONTINUUM
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?’
