Handbook of Psychology

148 Tobacco Dependence

positive effects, mediated by alterations in neurotrans-
mitter levels, give way to negative, withdrawal effects in the
absence of nicotine among dependent tobacco users.
Withdrawal symptoms include anger/irritability, anxiety,
dif“culty concentrating, drowsiness, fatigue, hunger/weight
gain, impatience, and restlessness (Hughes, Gust, Skoog,
Keenan, & Fenwick, 1991). These symptoms tend to manifest
in the “rst 24 hours, peak in the “rst 1 to 2 weeks, and gener-
ally resolve within 30 days after quitting. Although many pa-
tients report cravings for cigarettes many months or years after
quitting.
An estimated 47.2 million Americans smoke (Centers for
Disease Control and Prevention, 2000); 70% want to quit
completely (Centers for Disease Control and Prevention,
1994); and each year, approximately 17 million adult smok-
ers in the United States make a serious attempt to quit.
Despite decades of research into improving methods for at-
taining cessation, smoking quit rates remain low„annually ,
only an estimated 2.5% are able to quit permanently (Centers
for Disease Control and Prevention, 1993). Economically, the
burden of smoking is enormous, costing the United States an
estimated $72 billion annually in lost productivity and med-
ical care (Horgan, Marsden, & Larson, 1993).
Figure 7.1, a summary of numerous studies (Chassin,
Presson, Sherman, & Edwards, 1990; Choi, Pierce, Gilpin,
Farkas, & Berry, 1997; Flay, 1999; Gilpin, Lee, Evans, &
Pierce, 1994; Gritz et al., 1998; Jessor & Jessor, 1977;
Johnston, O•Malley, & Bachman, 1991, 1995; Kendler,
1999), illustrates the development of tobacco dependence.
Tobacco dependence consists of several identi“able phases
when viewed from a developmental perspective.

Following initial exposure to tobacco, an individual will

experiment with it and, assuming that the consequences of ex-

perimentation have provided more positive than negative con-

sequences, that individual will acquire regular tobacco use as

a feature of his or her behavioral repertoire. To the extent that

tobacco use itself acquires an instrumental component (e.g.,

helping the individual to cope with stress, manage weight, reg-

ulate affect), it will be maintained and, depending on the per-

son and environmental conditions, perhaps even strengthen

over time (increase in cigarettes smoked per day, for exam-

ple). There is the possibility that tobacco use will lessen

(smoking fewer cigarettes or •lighterŽ cigarettes) and perhaps

extinguish altogether. For many people desiring to quit, how-

ever, there begins a process of cessation-reacquisition-relapse

that commonly is repeated many times.

BASIC MECHANISMS OF NICOTINE ADDICTION

The diverse effects of nicotine on brain function are mediated

by activating nicotinic acetylcholine receptors (nACHRs).

The nACHRs are formed by the combination of “ve  and/or

subunits. Thus far, 11 subunits have been identi“ed in dif-

ferent neuronal populations, those being 2 to 9 and 2 to

4. In the brain, nACHRs can be divided into two subfami-

lies: homoligomeric receptors that are composed of identical

subunits (7,8, or 9 subunits); and heteromeric receptors

that are composed of varying combinations of 2,3,4,

and6 with either 2 or 4 and in some cases also with 5or

3 subunits (Clementi, Fornasari, & Gotti, 2000; Paterson &

Nordberg, 2000). The nACHRs are found on the cell body

Exposure

Experimentation

AcquisitionMaintenanceExtinctionCessation

Reacquisition

Relapse Cycling

Depression

ADHD

Anti-social

personality

Neuroticism

Gender

Metabolism

Brain reward

system

Brain opioid

system

Brain

serotonergic

system

Stress

End-organ changes

Receptor function

and density

Heightened

concentration

Mood alterations

Withdrawal sxs

Weight loss

Boredom

Dysphoria

Demand for vigilance

Demand for thinness

Parental smoking

Peer influences

Advertising

Preexisting Conditions Environmental Conditions Secondary Conditions

Figure 7.1 A working model of genetic and environmental factors in the developmental span

of smoking.