Cigarettes and Other Nicotine
Nicotine is one of the most heavily used addictive drugs in the
United States. Cigarette smoking has been the most popular method
of taking nicotine since the beginning of the 20th century. In
1998, 60 million Americans were current cigarette smokers (28
percent of all Americans aged 12 and older), and 4.1 million were
between the ages of 12 and 17 (18 percent of youth in this age
In 1989, the U.S. Surgeon General issued a report that concluded
that cigarettes and other forms of tobacco, such as cigars, pipe
tobacco, and chewing tobacco, are addictive and that nicotine
is the drug in tobacco that causes addiction. In addition, the
report determined that smoking was a major cause of stroke and
the third leading cause of death in the United States.
Nicotine is highly addictive. It is both a stimulant and a sedative
to the central nervous system. The ingestion of nicotine results
in an almost immediate "kick" because it causes a discharge
of epinephrine from the adrenal cortex. This stimulates the central
nervous system, and other endocrine glands, which causes a sudden
release of glucose. Stimulation is then followed by depression
and fatigue, leading the abuser to seek more nicotine. Nicotine
is absorbed readily from tobacco smoke in the lungs, and it does
not matter whether the tobacco smoke is from cigarettes, cigars,
Nicotine also is absorbed readily when tobacco is chewed. With
regular use of tobacco, levels of nicotine accumulate in the body
during the day and persist overnight. Thus, daily smokers or chewers
are exposed to the effects of nicotine for 24 hours each day.
Nicotine taken in by cigarette or cigar smoking takes only seconds
to reach the brain but has a direct effect on the body for up
to 30 minutes.
Research has shown that stress and anxiety affect nicotine tolerance
and dependence. The stress hormone corticosterone reduces the
effects of nicotine; therefore, more nicotine must be consumed
to achieve the same effect. This increases tolerance to nicotine
and leads to increased dependence. Studies in animals have also
shown that stress can directly cause relapse to nicotine self-administration
after a period of abstinence.
Other studies have shown that animals cannot discriminate between
the effects of nicotine and the effects of cocaine. Studies have
also shown that nicotine self-administration sensitizes animals
to self-administer cocaine more readily. Addiction to nicotine
results in withdrawal symptoms when a person tries to stop smoking.
For example, a study found that when chronic smokers were deprived
of cigarettes for 24 hours, they had increased anger, hostility,
and aggression, and loss of social cooperation. Persons suffering
from withdrawal also take longer to regain emotional equilibrium
following stress. During periods of abstinence and/or craving,
smokers have shown impairment across a wide range of psychomotor
and cognitive functions, such as language comprehension.
Women who smoke generally have earlier menopause.
If women smoke cigarettes and also take oral contraceptives, they
are more prone to cardiovascular and cerebrovascular diseases
than are other smokers; this is especially true for women older
Pregnant women who smoke cigarettes run an increased
risk of having stillborn or premature infants or infants with
low birthweight. Children of women who smoked while pregnant have
an increased risk for developing conduct disorders. National studies
of mothers and daughters have also found that maternal smoking
during pregnancy increased the probability that female children
would smoke and would persist in smoking.
Adolescent smokeless tobacco users are more likely than nonusers
to become cigarette smokers. Behavioral research is beginning
to explain how social influences, such as observing adults or
other peers smoking, affect whether adolescents begin to smoke
cigarettes. Research has shown that teens are generally resistant
to many kinds of anti-smoking messages.
In addition to nicotine, cigarette smoke is primarily composed
of a dozen gases (mainly carbon monoxide) and tar. The tar in
a cigarette, which varies from about 15 mg for a regular cigarette
to 7 mg in a low-tar cigarette, exposes the user to a high expectancy
rate of lung cancer, emphysema, and bronchial disorders. The carbon
monoxide in the smoke increases the chance of cardiovascular diseases.
The Environmental Protection Agency has concluded that secondhand
smoke causes lung cancer in adults and greatly increases the risk
of respiratory illnesses in children and sudden infant death.
Research has shown that nicotine, like cocaine, heroin, and
marijuana, increases the level of the neurotransmitter dopamine,
which affects the brain pathways that control reward and pleasure.
Scientists now have pinpointed a particular molecule (the beta
2 subunit of the nicotine cholinergic receptor) as a critical
component in nicotine addiction. Mice that lack this molecule
fail to self-administer nicotine, implying that without the b2
molecule, the mice do not experience the positive reinforcing
properties of nicotine. This new finding identifies a potential
site for targeting the development of anti-nicotine addiction
Other new research found that individuals have greater resistance
to nicotine addiction if they have a genetic variant that decreases
the function of the enzyme CYP2A6. The decrease in CYP2A6 slows
the breakdown of nicotine and protects individuals against nicotine
addiction. Understanding the role of this enzyme in nicotine addiction
gives a new target for developing more effective medications to
help people stop smoking. Medications might be developed that
can inhibit the function of CYP2A6, thus providing a new approach
to preventing and treating nicotine addiction.
Another study found dramatic changes in the brain's pleasure
circuits during withdrawal from chronic nicotine use. These changes
are comparable in magnitude and duration to similar changes observed
during the withdrawal from other abused drugs such as cocaine,
opiates, amphetamines, and alcohol. Scientists found significant
decreases in the sensitivity of the brains of laboratory rats
to pleasurable stimulation after nicotine administration was abruptly
stopped. These changes lasted several days and may correspond
to the anxiety and depression experienced by humans for several
days after quitting smoking "cold turkey." The results
of this research may help in the development of better treatments
for the withdrawal symptoms that may interfere with individual's
attempts to quit smoking.
Research suggests that smoking cessation should be a gradual
process because withdrawal symptoms are less severe in those who
quit gradually than in those who quit all at once. Rates of relapse
are highest in the first few weeks and months and diminish considerably
after 3 m-onths.
Studies have shown that pharmacological treatment combined with
psychological treatment, including psychological support and skills
training to overcome high-risk situations, results in some of
the highest long-term abstinence rates.
Behavioral economic studies find that alternative rewards and
reinforcers can reduce cigarette use. One study found that the
greatest reductions in cigarette use were achieved when smoking
cost was increased in combination with the presence of alternative
Nicotine chewing gum is one medication approved by the Food and
Drug Administration (FDA) for the treatment of nicotine dependence.
Nicotine in this form acts as a nicotine replacement to help smokers
quit the smoking habit.
The success rates for smoking cessation treatment with nicotine
chewing gum vary considerably across studies, but evidence suggests
that it is a safe means of facilitating smoking cessation if chewed
according to instructions and restricted to patients who are under
Another approach to smoking cessation is the nicotine transdermal
patch, a skin patch that delivers a relatively constant amount
of nicotine to the person wearing it. A research team at NIDA's
Division of Intramural Research studied the safety, mechanism
of action, and abuse liability of the patch that was consequently
approved by FDA. Both nicotine gum and the nicotine patch, as
well as other nicotine replacements such as sprays and inhalers,
are used to help people fully quit smoking by reducing withdrawal
symptoms and preventing relapse while undergoing behavioral treatment.
Another tool in treating nicotine addiction is a medication that
goes by the trademark Zyban. This is not a nicotine replacement,
as are the gum and patch. Rather, this works on other areas of
the brain, and its effectiveness is in helping to make controllable
nicotine craving or thoughts about cigarette use in people trying
In the future, a nicotine vaccine may be an effective method
for preventing and treating tobacco addiction. The vaccine would
prevent nicotine from reaching the brain so as to reduce its effects
and help keep people from becoming addicted.
Scientists recently developed an experimental nicotine vaccine
consisting of a nicotine derivative attached to a large protein.
The scientists injected a single dose of nicotine into vaccinated
rats and found that the amount of nicotine reaching the brain
was reduced by 64%. Further, the researchers found that administering
doses of nicotine antibodies similar to those that are ordinarily
produced by the vaccine greatly reduced the rise in blood pressure
produced by a nicotine injection. The antibodies also completely
prevented the increased movements ordinarily seen when rats are
injected with nicotine.
The next steps will be to conduct additional safety studies,
followed by clinical trials with the vaccine in human volunteers.
These clinical trials are currently scheduled to begin in early
Extent of Use
Monitoring the Future Study (MTF)*
Prevalence rates for smoking among young people remain high,
in spite of the demonstrated health risk associated with smoking.
Since 1975, cigarettes have consistently been the substance the
greatest number of high school students use daily.
Between 1998 and 1999, however, past month smoking decreased
significantly among 8th graders, from 19.1 percent to 17.5 percent,
and rates of use were stable or slightly decreased for 10th graders
(25.7 percent) and seniors (34.6 percent). Lifetime and daily
use also leveled off in 1999 among all grades, as did use of smokeless
Cigarette Use by Students, 1999
Monitoring the Future Study
in Past Year*
|Used in Past
National Household Survey on Drug Abuse (NHSDA)**
Each year, the NHSDA reports on the nature and extent of drug
use among the American household population aged 12 and older.
In 1998, an estimated 60 million Americans, or 28 percent of all
Americans aged 12 and older, were current smokers. Approximately
18 percent (4.1 million) of youths 12 to 17 years old were current
smokers in 1998.
The 1998 survey shows that current smokers are more likely to
drink heavily and use illicit drugs than non-smokers.
Consequences of Use
The U.S. Surgeon General has confirmed that nicotine in tobacco
products has addictive properties similar in severity to those
of heroin. Quitting is difficult because of the unpleasantness
of withdrawal, which involves feelings of irritability, frustration,
anger, anxiety, insomnia, and depression. However, continued smoking
may lead to far more dire circumstances:
- Lung cancer
- Heart attacks
- High blood pressure
Other Sources of Information
Drug Abuse Information and Treatment
800-662-HELP; Spanish 800-66-AYUDA
Narcotics Anonymous and Nar-Anon Family Group
Nationwide referral line: 202-399-5316
National Institute on Drug Abuse
5600 Fishers Lane, Room 10-05
Rockville, MD 20857
NATIONWIDE HELPLINE: 800-662-HELP
American Society of Addiction Medicine
4601 North Park Avenue
Suite 101, Upper Arcade
Chevy Chase, MD 20815
American Academy of Addiction Psychiatry
7301 Mission Road, Suite 252
Prairie Village, KS 66208
# "Lifetime" refers
to use at least once during a respondent's lifetime. "Past
year" refers to an individual's drug use at least once during
the year preceding their response to the survey. "Past month"
refers to an individual's drug use at least once during the month
preceding their response to the survey.
* The MTF survey is conducted by the
University of Michigan's Institute for Social Research and is
funded by National Institute on Drug Abuse, National Institutes
of Health; it has tracked 12th graders' illicit drug use and related
attitudes since 1975. In 1991, 8th and 10th graders were added
to the study. For the 1999 study, 45,000 students were surveyed
from a representative sample of 433 public and private schools
nationwide. The latest survey data are available at NIDA's website,
and at the University of Michigan website,
** NHSDA is an annual survey conducted
by the Substance Abuse and Mental Health Services administration.
Copies of the latest survey are available from the National Clearinghouse
for Alcohol and Drug Information at 1-800-729-6686