Psychology Mod 22:
Drugs
Mrs. McVey
Mod 22 page 408
Psychoactivity & Dependence

Psychoactive drug is a chemical substance
that alters perceptions, mood, or behavior

Dependence: A state of physiological and/or
psychological need to take more of a
substance after continued use. Withdrawal
follows if the drug is discontinued.

Dependence becomes addiction when it disrupts
a person’s ability to function in everyday life
Psychoactivity & Dependence

Withdrawal: the discomfort and distress that
follow when a person who is dependent on a
drug discontinues the use of that drug.

Tolerance: Reduced responsiveness to a
drug, prompting the user to increase dosage
to achieve effects previously obtained by
lower doses
Drugs & Neurotransmission


Remember CNS? Neurons? Neurotransmitter?
Psychoactive drugs get into your synapses and
affect neurotransmission in three ways:


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Binding with receptors or mimicking a neurotransmitter’s
effect, which causes neurons to fire in the absence of
normal stimulation
Blocking receptor sites, preventing neurotransmitters from
binding, and thereby not allowing neurotransmission to
occur
Blocking neurotransmitter reabsorption intensifying the
neurotransmitter’s effect in the synapse
Drugs & Neurotransmission



Psychoactive drugs often bind BETTER and
stay attached to receptors LONGER than
normal neurotransmitters do, intensifying the
drug’s impact on the body.
Psychoactive drugs affect neurotransmission
by binding with receptors, blocking
neurotransmitter release, or blocking
reabsorption
See Figure 22.2 on page 411
Drug Classifications

Five different categories





Depressants
Opiates
Stimulants
Hallucinogens
Marijuana
Drug Classifications
Depressants: Drugs that reduce neural activity and
slow body function
 **Alcohol: shuts down parts of your brain
responsible for controlling inhibitions and making
judgments
 Sedatives: drugs that depress the activity of the
central nervous system, reducing anxiety but
impairing memory and judgment
(ex: Valium and Xanax)
Barbiturates are prescribed as tranquilizers

Drug Classifications



Opiates: Opium and its derivatives, such as
morphine and heroin, they depress neural
activity, temporarily lessening pain and
anxiety
Morphine: strong sedative and pain-relieving
drug derived from opium
Endorphins: natural, opiatelike
neurotransmitters linked to pain control and
pleasure (exercise endorphins)
Drug Classifications





Stimulants: drugs that excite neural activity and
speed up body functions
Caffeine: stimulant found in coffee, chocolate, tea,
and soft drinks (**caffeine withdrawal=moody,
headaches) tolerance with regular use
Nicotine: stimulant found in tobacco
Cocaine: stimulant derived from leaves of coca pant
Amphetamines: drugs stimulate neural activity,
speeding up body functions, and associated energy
and mood changes (speed or uppers)
Drug Classifications



Hallucinogens: Psychedelic (“mind-manifesting”)
drugs such as LSD and ecstasy, that distort
perceptions and evoke sensory images in the
absence of sensory input
LSD : powerful hallucinogen drug also known as
acid
Ecstasy: hallucinogen that produces lowered
inhibitions, pleasant feelings, and greater
acceptance of others. Even moderate use may
result in permanent brain damage
Drug Classifications


Marijuana: leaves, stems, resin, and flowers from
the hemp plant that, when smoked, lower inhibitions
and produced feelings of relaxation and mild
euphoria
Medical Marijuana

Has its own category because:
 its behavioral effects are similar to low doses of alcohol,
but different than high doses because it doesn’t suppress
breathing and isn’t lethal
 It produces very mild hallucinogenic experiences
 Chemical structure doesn’t resemble sedatives or
hallucinogens
Long-term costs of Marijuana

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Pot smoke is harder on your lungs than cigarette
smoke
Brain cell loss accelerates with large doses
Memory is still impaired long after marijuana’s effect
has worn off
Marijuana seems to suppress the immune system,
making it harder for your body to fight off disease
and infection
The structure of every hair on your body is
detectably damaged with even a single marijuana
experience, and no amount of conditioner can hide
the damage
Prevention

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Education is related to drug use—15% of US
college dropouts smoke, as do 42% of high school
dropouts
Hope matters—Those who believe their lives are
meaningless are more likely to do drugs
Genetics play a role: there is a gene occurring more
frequently among alcohol-dependent people than
among others
Peers count—if friends do not drink or smoke, teens
are more likely not to do it.
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Psychology Mod 22: Drugs