432 CHAPTER 9
Summary of Use, Abuse,
and Dependence
The hallmark of substance use disorders is
abuse of or dependence on a psychoactive
substance. The term addiction focuses on
the compulsive behaviors related to regular
drug taking, but is not used in DSM-IV-TR.
Substance abuse refers to the pattern of use
of a psychoactive substance that leads to
harmful effects; substance dependence re-
fers to the persistent and compulsive use of a
psychoactive substance, despite the ensuing
negative consequences. Tolerance and with-
drawal are common symptoms of substance
dependence.
Researchers have developed two compat-
ible explanations of why substance use may
lead to abuse. The common liabilities model
focuses on underlying factors that may con-
tribute to a variety of problematic behaviors,
including substance abuse. The gateway
hypothesis focuses on factors that lead indi-
viduals to progress from using entry drugs to
using harder drugs.
In DSM-IV-TR, substance abuse and de-
pendence are characterized as discrete cat-
egories; some researchers suggest that they
may be better conceptualized as being on
a continuum. Substance use disorders fre-
quently co-occur with mood disorders (par-
ticularly depression), PTSD, schizophrenia,
and ADHD. Many people with substance use
disorders engage in polysubstance abuse.
Cultures can promote or regulate substance
use through the use of rituals and penalties.Thinking like a clinician
Jorge and his friend Rick worked hard and
played hard in high school. On weekend
evenings, usually their only free time, they’d
binge drink, along with others in their group.
They went to different colleges. Jorge kept
up his “study hard, party hard” lifestyle; Rick
didn’t do much binge drinking in college, but
he started smoking marijuana in the eve-
nings when he was done studying and he’d go
dancing on Saturday nights and sometimes
take Ecstasy or stimulants. What information
would you want to know in order to determine
whether Jorge or Rick had a substance use
disorder? How would you know whether ei-
ther was dependent on a substance?Summary of Stimulants
Stimulants, which increase arousal and brain
activity, are the category of psychoactive
substances most likely to lead to depen-
dence. Unlike many other types of drugs,they act directly—rather than indirectly—on
the dopamine reward system by binding to
dopamine transporters in the synapse. Stim-
ulants include cocaine and crack, amphet-
amines, methamphetamine, Ritalin, MDMA,
and nicotine. Crack use is associated with
the most rapid progression to dependence.
In high doses, most of these stimulants can
cause paranoia and hallucinations. With con-
tinued use, stimulants lead to tolerance and
withdrawal.
Neurological factors that contribute to
abuse of and dependence on stimulants in-
clude activation of the dopamine reward sys-
tem, which involves the nucleus accumbens
and the ventral tegmental area.
Psychological factors related to substance
use disorders include learning: operant rein-
forcement of the effects of the drug, classical
conditioning of stimuli related to drug use
(which leads to cravings), and observational
learning of expectancies about both the ef-
fects of drugs and the use of them to cope
with problems.
Social factors related to substance use
disorders include the specifi c nature of an in-
dividual’s relationships with family members,
socioeconomic factors, and cultural and per-
ceived norms about appropriate and inappro-
priate use of substances.Thinking like a clinician
One night before a major class project was
due, Sierra had hours of work left to do, and
she’d had all the coffee she could stand. She
took one of her roommate’s Ritalin pills and
stayed up all night, completing the project
by morning. Sierra gradually got in the habit
of using amphetamines to help her stay up
late and do course work. After college, Sierra
took a job with lots of deadlines and lots of
late hours. She continued to use stimulants
to help her work, sometimes taking cocaine
when she could get it.
At what point does Sierra’s use of stim-
ulants become abuse? Does she have a
dependence—why or why not? What would be
some specifi c symptoms that would indicate
that she was abusing cocaine? What symp-
toms would you expect to see if Sierra were
taking a high dose of stimulants? According to
the neuropsychosocial approach, what factors
might have led Sierra to abuse stimulants, if
she were abusing them?Summary of Depressants
Depressants decrease arousal, awareness,
and nervous system activity level. Depres-
sants include alcohol, barbiturates, andbenzodiazepines. Continued use of depres-
sants leads to tolerance and withdrawal. Some
withdrawal symptoms are potentially lethal;
people with a dependence on depressants
should be medically supervised as they taper
off their use of the drug. Using more than one
depressant at the same time is also potentially
lethal.
Depressants directly affect the GABAner-
gic system, which in turn dampens activity in
key brain areas that give rise to anxiety; for
this reason, people with anxiety symptoms
are more likely than others to abuse depres-
sants. Depressants also indirectly activate the
dopamine reward system.
Psychological factors related to depres-
sant abuse and dependence include observa-
tional learning to expect specifi c effects from
depressant use and to use depressants as a
coping strategy, positive and negative rein-
forcement of the effects of the drug, and clas-
sical conditioning of drug cues that leads to
cravings.
Social factors related to abuse of and de-
pendence on depressants include the specifi c
nature of an individual’s relationships with
family members, peers’ use of depressants,
norms and perceived norms about appropri-
ate and inappropriate use of depressants, and
socioeconomic factors.Thinking like a clinician
When you see your neighbor in the hallway
in the evenings, she sometimes can’t seem to
walk in a straight line, her speech is slurred,
and she reeks of alcohol. She frequently misses
when she tries to put her key in the lock and
begins giggling. Once you saw her vomit after
such an incident. On a few occasions, she hasn’t
been so obviously “wasted” and has turned to
you and roughly said, “What are you staring at?”
One time, when you smirked as she tried to put
her key in the lock, she came over to you and
threatened to “kick your butt.” Even during the
daytime, though, she’s not very nice or friendly.
Do you think your neighbor has a problem
with alcohol, and if so, is it abuse or depen-
dence? Why or why not—what supports or re-
futes the conclusion that she has an alcohol
problem? What information would you want
to know before making a confi dent decision?
According to the neuropsychosocial approach,
what factors might underlie your neighbor’s
use of alcohol?Summary of Other Abused
Substances
Narcotic analgesics, also called opioids, can
dull pain and decrease awareness. ContinuedSUMMING UP