Abnormal Psychology

384 CHAPTER 9

Two neurologically based symptoms of substance

dependence can contribute to the diagnosis: tolerance

and withdrawal (American Psychiatric Association,

2000). Tolerance occurs when, with repeated use,

more of the substance is required to obtain the same

effect (e.g., intoxication). For instance, someone who

drinks alcohol regularly is likely to develop tolerance

to alcohol and fi nd that it takes more drinks to ob-

tain a “buzz” and even more drinks to get drunk. As

shown in Figure 9.1, with regular use of alcohol and

some drugs, the body adapts and tries to compensate

for the repeated infl ux of the substance.

Withdrawal refers to the set of symptoms that

arises when a regular user decreases intake of the sub-

stance. As shown in Figure 9.1f, withdrawal arises

because the body has compensated for the repeated

infl ux of a drug and, when the person stops taking the drug, the neurological com-

pensatory mechanisms are still in place, but the drug is no longer there to coun-

terbalance them. Unfortunately, withdrawal symptoms can make it diffi cult for

habitual users of some substances to cut back or stop their use: As they cut back,

they may experience uncomfortable or even life-threatening symptoms that are tem-

porarily alleviated by resuming use of the substance.

In most cases, substances that can lead to tolerance with regular use are also

likely to produce withdrawal symptoms if stopped or taken at lower doses. There

are some exceptions—substances for which tolerance may develop but with-

drawal symptoms do not arise. For example, this is the case with LSD (lysergic

acid diethylamide, a hallucinogen). In contrast, chronic marijuana use can lead

to withdrawal symptoms, but the individual may not necessarily experience toler-

ance. Regular use of other substances, such as PCP (phencyclidine), causes neither

tolerance nor withdrawal, and a diagnosis of dependence on this drug relies on

other symptoms.

Table 9.3 • DSM-IV-TR Diagnostic Criteria for Substance Dependence

A maladaptive pattern of substance use, leading to clinically signifi cant impairment or distress, as

manifested by three (or more) of the following, occurring at any time in the same 12-month period:

(1) Tolerance, as defi ned by either of the following:

(a) a need for markedly increased amounts of the substance to achieve intoxication or

desired effect

(b) markedly diminished effect with continued use of the same amount of the substance

(2) Withdrawal, as manifested by either of the following:

(a) the characteristic withdrawal syndrome for the substance

(b) the same (or a closely related) substance is taken to relieve or avoid withdrawal symptoms

(3) The substance is often taken in larger amounts or over a longer period than was intended

(4) There is a persistent desire or unsuccessful efforts to cut down or control substance use

(5) A great deal of time is spent in activities necessary to obtain the substance (e.g., visiting

multiple doctors or driving long distances), use the substance (e.g., chain-smoking), or

recover from its effects

(6) Important social, occupational, or recreational activities are given up or reduced because of

substance use

(7) The substance use is continued despite knowledge of having a persistent or recurrent physical

or psychological problem that is likely to have been caused or exacerbated by the substance

(e.g., current cocaine use despite recognition of cocaine-induced depression, or continued

drinking despite recognition that an ulcer was made worse by alcohol consumption).

Source: Reprinted with permission from the Diagnostic and Statistical Manual of Mental Disorders, Text Revision,

Fourth Edition, (Copyright 2000) American Psychiatric Association.

9.1 • Tolerance and Withdrawal

Using a see-saw as a metaphor for the

body’s response to repeated drug use,

this fi gure illustrates the progression

to tolerance and withdrawal: (a) no

drug use; (b) an imbalance arises

from drug use; (c) the brain and body

adapt to the drug, and tolerance

begins; (d) more of the drug is taken to

overcome tolerance; (e) the brain and

body adapt to this higher level of drug

use; (f) because of the adaptation, when

drug use is discontinued (or reduced)

that adaptation creates withdrawal

symptoms.

Source: Adapted from Goldstein, 1994.

Figure 9.1g9

(a) Normal (b) Drug effect (c) Adaptation (tolerance)

(d) Drug effect overcomes

tolerance

(e)

Drug

Drug

Drug

Drug BCR

Note: BCR stands for “body’s compensatory response.”

Drug BCR

BCR

BCR

BCR

Drug

BCR

Tolerance; condition (f ) Withdrawal

apparently normal,

dependence masked