
Broadly speaking, a drug is any substance
that, when absorbed into the body of a
living organism, alters normal bodily
function.
There is no single, precise definition, as there
are different meanings in drug control law,
government regulations, medicine, and
recreational usage
 We will view the term drug through three
different perspectives: medical utility,
illegality, psychoactivity


According to the Medical Utility model, a
drug is defined as a substance that is
used to treat or heal the body or mind

Here, drugs are used to return the user to
a state of normalcy, removing that
which is pathological, abnormal or
unnatural

Examples: Penicillin, Aleve, Benadryl

A psychoactive drug is any substance
that has an effect on the mind
Cocaine
 Alcohol
 Vicodin
 Marijuana


In defining a drug based on the
substance’s legal status, it would have to
be determined whether possession or
sale of the substance is legal or illegal.
Alcohol (example: 4Loko)
 Marijuana
 Tylenol w/Codeine


Instrumental: users take the drug out of
necessity
› Example: Using Xanax to quell anxiety

Recreational: users take the drug simply
to achieve a “buzz” or “high”
› Example: Smoking marijuana to “feel good”

Here, we are looking at the impact of
drugs on the mind

The actions of some drugs can conduce
(lead/contribute to) certain behaviors

Many drugs have extreme toxicity, and
others produce a powerful dependence
in users

Drug abuse refers to a maladaptive pattern
of use of a substance that is not considered
dependent

Dependence refers to the continued use of
the drug despite problems related to use of
the substance. Compulsive and repetitive
use may result in tolerance to the effect of
the drug and withdrawal symptoms when
use is reduced or stopped
› Physical: a process by which the body
adjusts to and comes to need the drug for its
everyday functioning.
› Psychological: a desire to obtain or use a
drug even though the physical dependence
is not present

Acute: one’s immediate reaction to
taking a drug, ie: overdose, motor
discoordination

Chronic: the long term results of
continued usage of a substance, ie:
cirrhosis of the liver after 30 years of
heavy drinking, lung cancer after
decades of smoking

Pharmacological: over time, neurons
become increasingly insensitive to a drug,
so the drug becomes decreasingly
ineffective

Cross: use of one drug leads to tolerance of
a similar drug, ie: tolerance of heroin will
produce tolerance to morphine, both are
narcotics

Behavioral: refers to an experienced users
compensation for the effects of a given
drug, ie: an experienced drinker may have
trained themselves to “drive” under the
influence, as opposed to someone who has
taken a few drinks and gotten behind the
wheel for the first time.

Intravenously (IV)

Smoking

Inhalation

Oral

Depressants: temporarily reduce the
function or activity of a specific part of
the body or brain. Also known as
“downers”

When used, the effects may include
cognitive/memory impairment, muscle
relaxation, lowered blood pressure/heart
rate, and possible feelings of euphoria

Stimulants: induce temporary improvements
in either mental or physical function or both.
Also known as “uppers”

These kinds of effects may include
enhanced alertness, wakefulness, and
locomotion, among others. Feelings of
euphoria may also be felt, however, many
stimulants can also cause anxiety and heart
failure.

Hallucinogens: can cause subjective
changes in perception, thought,
emotion and consciousness

Dissociative Anesthetics: reduce or block
signals to the conscious mind from other
parts of the brain, yet they have the
ability to induce hallucinogenic effects

Narcotics are powerful drugs that give
users feelings of euphoria, yet have a
notably powerful sleep-inducing
property