Download Chapter 15

PRINCIPLES OF DRUG
ACTION
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Outline
1. The Drug Problem
2. Drug Tolerance & Withdrawal
3. Role of Learning in Drug Tolerance
and Withdrawal
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a. Contingent Drug Tolerance
b. Conditioned Drug Tolerance
c. Conditioned Withdrawal
Which drugs are most
addictive?
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Two sets of standards
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Legal standards
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Set by the Controlled Substances Act of 1970
Five different schedules of drugs
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Note that alcohol and nicotine are not on the drug
schedule
Can be bought without prescription
Scientific standards
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Reflected by expert views of addictive potential
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Two experts rated
abuse potential of
various drugs
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Jack Henningfield,
formerly Chief of Clinical
Pharmacology at the
Addiction Research
Center at NIDA
Neil Benowitz, addiction
researcher at University
of California at San
Francisco
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1) presence and severity
of withdrawal
2) how reinforcing the
drug is (from human and
animal studies)
3) the degree of tolerance
produced by the drugs
4) degree of dependence
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Difficulty quitting
Relapse
5) degree of intoxication
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Overall rankings
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Heroin (1.9)
Alcohol (2.5)
Cocaine (2.65)
Nicotine (3.35)
Caffeine (5.0)
Marijuana (5.4)
Two of the top 4 substances
are legal
Marijuana is lowest on this
list, but a schedule 1 drug.
Keep in mind long term
consequences were not
included.
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Note that low numbers
indicate the most
serious abuse potential
Also note how closely
the two experts rated
the drugs on the
various measures
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Physical dependence
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Psychological dependence
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What does it mean to be addicted?
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American Psychiatric Association has
stopped using the term addiction and
addict in their professional writing
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Due to bad connotation
They use the term substance related
disorders
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Two general disorders
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Substance Dependence (more severe)
Substance Abuse
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Note that merely using a drug, even if it
is illegal, does not necessarily indicate a
substance related disorder
The use must be maladaptive
Contingent Drug Tolerance
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Ethanol-before group
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received an ethanol injection once every 48 hours
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Ethanol is an anticonvulsant
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repeatedly experience this effect
Ethanol-after group
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received ethanol injections on the same bi-daily schedule
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1 hour before a convulsive amygdala stimulation
1 hour after each convulsive stimulation
Never experience ethanol's anticonvulsant effect
Test
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only the rats in the ethanol-before-stimulation group
were tolerant to alcohol's anticonvulsant effect
Crowell, Hinson, and Siegel
(1981)
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Two groups of rats
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Manipulation of context
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20 alcohol injections
20 saline injections
alternating sequence
one every 48 hours.
alcohol in context 1 (test room)
saline in context 2 (colony room)
Tolerance only occurred when the subjects were tested in the
same environment in which they had previously received alcohol