268 Unit 4 Understanding and Avoiding Hazardous Substances
Copyright Goodheart-Willcox Co., Inc.
Experimentation
Initially, people often choose to use a substance such as cigarettes or
chewing tobacco “just to try it.” This is the stage of experimentation, when
a person is trying a substance and, potentially, using it more regularly.
Experimentation with a substance often leads to the regular use of a
substance.
Regular Use
After initially trying a substance, people may gradually increase their
substance use. Over time, people who smoke a few cigarettes may slowly
increase the amount of times they smoke per week. Users are then likely to
develop a regular pattern of smoking cigarettes.
Tolerance
People who regularly use a substance develop a tolerance for that sub-
stance. A tolerance develops when the body needs greater amounts of a
substance to experience the effects it felt when a lesser amount was used.
The body can quickly develop a tolerance to nicotine and require more
cigarettes to achieve the original effect.
Dependency and Addiction
After repeated use, the body adjusts to—or becomes dependent on—the
feelings that result from the presence of nicotine. Dependence occurs when
the body relies on the presence of an addictive substance in the system
to function “normally” or feel “normal.” There are two types of depen-
dence—physical and psychological.
Figure 9.8 Stages of Substance Abuse
Stage one: experimentation Experimentation with a substance begins.
Substance use may stop at this stage, or
may rapidly develop into other stages.
Stage two: regular use The user develops a habit of regularly using
a substance.
Stage three: tolerance The user’s body develops a tolerance to the
substance. Gradually, the user feels the need
for more and more of a substance to achieve
the same effects as before.
Stage four: dependence and
addiction
The user becomes reliant on having the
substance present in the body to function
normally or feel “normal.” Substance use
also interferes with personal responsibilities
and relationships. The user is physically and
psychologically addicted to the substance.
tolerance
a condition in which the
body adjusts to given
substance, requiring
increased amounts of the
substance to feel its effect
dependence
a condition in which a
person relies on a given
substance to function or
feel normal