17 SUBSTANCEABUSE 411
substance abuse is featured near the end of this
chapter. The effects on adults who grew up in a home
with an alcoholic parent are discussed later as are
the special needs of clients with a dual diagnosis of
substance use and a major psychiatric disorder.
ETIOLOGY
The exact causes of drug use, dependence, and addic-
tion are not known, but various factors are thought to
contribute to the development of substance-related
disorders (Jaffe, 2000c). Much of the research on bio-
logic and genetic factors has been done on alcohol
abuse, but psychological, social, and environmental
studies have examined other drugs as well.
Biologic Factors
Children of alcoholic parents are at higher risk for
developing alcoholism and drug dependence than are
children of nonalcoholic parents (Jaffe, 2000c). This in-
creased risk is partly the result of environmental fac-
tors, but evidence points to the importance of genetic
factors as well. Several studies of twins have shown a
higher rate of concordance (when one twin has it, the
other twin gets it) among identical than fraternal
twins. Adoption studies have shown higher rates of
alcoholism in sons of biologic fathers with alcoholism
than in those of nonalcoholic biologic fathers. These
studies lead theorists to describe the genetic compo-
nent of alcoholism as a genetic vulnerability that is
then influenced by various social and environmental
factors. Slutske, Heaht, Madden, Bucholz, Statham &
Martin (2002) found that 50% to 60% of the variation
in causes of alcoholism was the result of genetics, with
the remainder caused by environmental influences.
Neurochemical influences on substance use pat-
terns have been studied primarily in animal research
(Jaffe, 2000c). The ingestion of mood-altering sub-
stances stimulates dopamine pathways in the limbic
system, which produces pleasant feelings or a “high”
that is a reinforcing, or positive, experience. Distri-
bution of the substance throughout the brain alters
the balance of neurotransmitters that modulate plea-
sure, pain, and reward responses. Researchers have
proposed that some people have an internal alarm
that limits the amount of alcohol consumed to one or
two drinks, so that they feel a pleasant sensation but
go no further. People without this internal signaling
mechanism experience the high initially but con-
tinue to drink until central nervous system depres-
sion is marked and they are intoxicated.
Psychological Factors
In addition to the genetic links to alcoholism, family
dynamics are thought to play a part. Children of alco-
holics are four times as likely to develop alcoholism
(Schuckit, 2000) compared to the general population.
Some theorists believe that inconsistency in the par-
ent’s behavior, poor role modeling, and lack of nurtur-
ing pave the way for the child to adopt a similar style
of maladaptive coping, stormy relationships, and sub-
stance abuse. Others hypothesize that even children
who abhorred their family lives are likely to abuse
substances as adults because they lack adaptive cop-
ing skills and cannot form successful relationships
(Brown University Digest, 2002).
Some people use alcohol as a coping mechanism
or to relieve stress and tension, increase feelings of
power, and decrease psychological pain. High doses
of alcohol, however, actually increase muscle tension
and nervousness (Schuckit, 2000).Social and Environmental Factors
Cultural factors, social attitudes, peer behaviors,
laws, cost, and availability all influence initial and
continued use of substances (Jaffe, 2000c). In gen-
eral, younger experimenters use substances that carry
less social disapproval such as alcohol and cannabis,
whereas older people use drugs such as cocaine and
opioids that are more costly and rate higher dis-
approval. Alcohol consumption increases in areas
where availability increases and decreases in areas
where costs of alcohol are higher because of increased
taxation. Many people view the social use of cannabis,
although illegal, as not very harmful; some even ad-
vocate legalizing the use of marijuana for social pur-
poses. Urban areas where cocaine and opioids are
readily available also have high crime rates, high un-
employment, and substandard school systems that
contribute to high rates of cocaine and opioid use and
low rates of recovery. Thus environment and social
customs can influence a person’s use of substances.CULTURAL CONSIDERATIONS
Attitudes toward substance use, patterns of use, and
physiologic differences to substances vary in different
cultures. Muslims do not drink alcohol, but wine is an
integral part of Jewish religious rites. Some Native
American tribes use peyote, a hallucinogen, in reli-
gious ceremonies. It is important to be aware of such
beliefs when assessing for a substance abuse problem.
Certain ethnic groups have genetic traits that
either predispose them to or protect them from devel-
oping alcoholism. For instance, flushing,a reddening
of the face and neck as a result of increased blood flow,
has been linked to variants of genes for enzymes in-
volved in alcohol metabolism. Even small amounts of
alcohol can produce flushing, which may be accompa-
nied by headaches and nausea. The flushing reaction