Transcript Drug

Chapter Twelve
Drugs and Addictive Behavior:
Use, Abuse, and Control
© 2007 McGraw-Hill Higher Education. All rights reserved.
What is a Drug?
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Drug: a substance other than food that affects the
structure or function of the body through its
chemical action
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Psychoactive drugs: substances that cause
changes in brain chemistry and alter
consciousness, perception, mood, and thought
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Drug of abuse: medical drugs used for non-medical
purposes or a drug that has no medical uses
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All drugs have the potential to be toxic, poisonous,
dangerous, or deadly
© 2007 McGraw-Hill Higher Education. All rights reserved.
Types of Drugs
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Drugs are classified in several different ways
Legal drugs include:
 Medication
prescribed by physicians
 Over the counter (OTC) medications
 Herbal remedies
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Illicit drugs are unlawful to possess, manufacture,
sell, or use
Table 12.2 summarizes the controlled substance schedules
© 2007 McGraw-Hill Higher Education. All rights reserved.
Drug Use, Misuse, and Abuse
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Drug use can refer to something as common
taking two aspirin for a headache
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Drug misuse: use of prescription drugs for
purposes other than those for which they were
prescribed or in greater amounts than prescribed
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Drug abuse: the use of a substance in amounts,
situations, or a manner such that it causes
problems, or greatly increases the risk of
problems, for the user or for others
© 2007 McGraw-Hill Higher Education. All rights reserved.
Routes of Administration
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Orally
Injection
 Usually
involves a hypodermic needle delivered into
the bloodstream by:
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Intravenous injection
Intramuscular injection
Subcutaneous injection
Inhalation
Application to skin or mucous membranes
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Dermal absorption
Transdermal absorption
© 2007 McGraw-Hill Higher Education. All rights reserved.
Factors Influencing the Effects of
Drugs
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Characteristics of the drug
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Characteristics of the person
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Chemical properties of the drug and its actions
Age
Gender
Body weight and mass
Physical condition
Mood
Experience with the drug
Expectations
Characteristics of the situation
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Environmental experience
© 2007 McGraw-Hill Higher Education. All rights reserved.
Drug Dependence
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A condition characterized by a strong craving for a drug and
by compulsive use of the drug despite serious negative
consequences
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Dependence usually means that physiological changes
have taken place in the brain and body chemistry
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Tolerance usually occurs because the body seeks to
compensate for the chemical imbalance caused by the drug
and achieves a ‘new normal’
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Withdrawal symptoms are different for different drugs and
lead to unpleasant feelings
© 2007 McGraw-Hill Higher Education. All rights reserved.
Effects of Drugs on the Brain
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Many addictive drugs act on neurons in three brain
structures:
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The ventral tegmental area (VTA) in the midbrain
Nucleus accumbens
Prefrontal cortex
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These neurons form a pathway called the Pleasure and
Reward Circuit (see Figure 12.2)
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Once drugs reach this area, productions of dopamine
increase
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All or nearly all addictive drugs operate via this pleasure and
reward circuit
© 2007 McGraw-Hill Higher Education. All rights reserved.
Addictive Behaviors
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Many experts now extend the concept of addiction
to other areas in which behavior can be compulsive
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Such as gambling, exercise, and sex
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These behaviors may follow the same pleasure
pathway as drugs do in the brain
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These behaviors produce a ‘high’, and the brain
adjusts in such a way that the person experiences
a strong desire to repeat the behavior as well as a
craving for the behavior when it stops
© 2007 McGraw-Hill Higher Education. All rights reserved.
Drugs of Abuse
Stimulants
 Depressants
 Opioids
 Hallucinogens
 Inhalants
 Marijuana
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© 2007 McGraw-Hill Higher Education. All rights reserved.
Central Nervous System
Stimulants
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Drugs that speed up activity in the brain and
sympathetic nervous system
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Effects evoke a ‘fight or flight’ response
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May produce intense feelings of euphoria and
create a sense of well-being
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Examples are:
 Caffeine
 Amphetamines
 Cocaine
 MDMA (ecstasy)
© 2007 McGraw-Hill Higher Education. All rights reserved.
CNS Depressants
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Slow down activity in the brain and sympathetic
nervous system
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Can be deadly if misused, especially when mixed
with alcohol
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CNS depressants carry a high risk of dependence
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Examples include:
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Barbiturates and Hypnotics
Anti-anxiety drugs (benzodiazepines)
Rohypnol
GHB (Gamma hydroxbutyrate)
© 2007 McGraw-Hill Higher Education. All rights reserved.
Opioids
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Natural and synthetic derivatives of opium
Have a long history of medical use for pain relief and
treatment of dehydration
Prescribed as pain relievers, anesthetics, antidiarrheal
agents, and cough suppressants
Examples include:
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Morphine
Heroin
Codeine
Oxycodone
Produce feelings of pleasure and block sensation of pain
© 2007 McGraw-Hill Higher Education. All rights reserved.
Hallucinogens
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Also known as psychedelics
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Alter perceptions and thinking in characteristic ways
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They produce intensification and distortion of visual and
auditory perceptions as well as hallucinations
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Schedule I drugs with no current medical uses
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Examples are:
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LSD (Lysergic acid diethylamide)
Psilocybin
Mescaline
PCP (Phencylclidine)
© 2007 McGraw-Hill Higher Education. All rights reserved.
Inhalants
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Breathable chemical vapors that alter
consciousness, typically producing a state of
intoxication that resembles drunkenness
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Commonly classified into 4 categories:
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Volatile solvents
Aerosols
Gases
Nitrates
The most significant negative effect for chronic
users is widespread and long-lasting brain damage
© 2007 McGraw-Hill Higher Education. All rights reserved.
Marijuana
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The most widely used illicit drug in the United States
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Marijuana is derived from the hemp plant, Cannabis sativa
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The active ingredient is delta-9-tetrahydrocannabinol (THC)
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Marijuana produces mild euphoria, sedation, lethargy, shortterm memory, impairment, distorted sensory perceptions, and
impaired coordination
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Researchers have found that THC has a variety of effects on
the brain, creating decision-making problems
© 2007 McGraw-Hill Higher Education. All rights reserved.
Demand Reduction Strategies
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Incarceration for Drug-related Crimes
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Prevention Strategies through Education
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Primary Prevention
Secondary Prevention
Tertiary Prevention
Drug Treatment Programs
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Narcotics Anonymous (NA)
© 2007 McGraw-Hill Higher Education. All rights reserved.
Chapter Twelve
Drugs and Addictive Behavior:
Use, Abuse, and Control
© 2007 McGraw-Hill Higher Education. All rights reserved.