from the director:

Tobacco use kills approximately 

440,000 Americans each year, with 

one in every five U.S. deaths the 

result of smoking. Smoking harms 

nearly every organ in the body, causes 

many diseases, and compromises 

smokers’ health in general. Nicotine, a 

component of tobacco, is the primary 

reason that tobacco is addictive, 

although cigarette smoke contains 

many other dangerous chemicals, 

including tar, carbon monoxide, 

acetaldehyde, nitrosamines, and 

more.

An improved overall understanding 

of addiction and of nicotine as an 

addictive drug has been instrumental 

in developing medications and 

behavioral treatments for tobacco 

addiction. For example, the nicotine 

patch and gum, now readily available 

at drugstores and supermarkets 

nationwide, have proven effective for 

smoking cessation when combined 

with behavioral therapy. 

Advanced neuroimaging technologies 

make it possible for researchers to 

observe changes in brain function 

that result from smoking tobacco. 

Researchers are now also identifying 

genes that predispose people to 

tobacco addiction and predict their 

response to smoking cessation 

treatments. These findings—

and many other recent research 

accomplishments—present unique 

opportunities to discover, develop, 

and disseminate new treatments 

for tobacco addiction, as well as 

scientifically based prevention 

programs to help curtail the public 

health burden that tobacco use 

represents.

We hope this Research Report will 

help readers understand the harmful 

effects of tobacco use and identify 

best practices for the prevention and 

treatment of tobacco addiction.

Nora D. Volkow, M.D.

Director

National Institute on Drug Abuse

Tobacco 

Addiction

What are 

the medical 

consequences 

of tobacco use?

See page 4.

continued inside

According to the 2010 National Survey on Drug Use 

and Health, an estimated 69.6 million Americans aged 

12 or older reported current use of tobacco—58.3 

million (23.0 percent of the population) were current cigarette 

smokers, 13.2 million (5.2 percent) smoked cigars, 8.9 million 

(3.5 percent) used smokeless tobacco, and 2.2 million (0.8 

percent) smoked pipes, confirming that tobacco is one of the 

most widely abused substances in the United States. Although 

the numbers of people who smoke are still unacceptably high, 

according to the Centers for Disease Control and Prevention 

there has been a decline of almost 50 percent since 1965. 

What Are the Extent and 

Impact of Tobacco Use?
Research Report Series

NIDA’s 2011 Monitoring the 

Future survey of 8th-, 10th-, and 

12th-graders, which is used to track 

drug use patterns and attitudes, has 

also shown a striking decrease in 

smoking trends among the Nation’s 

youth. The latest results indicate 

that about 6 percent of 8th-graders, 

12 percent of 10th-graders, and 

19 percent of 12th-graders had 

used cigarettes in the 30 days prior 

to the survey—the lowest levels 

in the history of the survey. 

The declining prevalence of 

cigarette smoking among the general 

U.S. population, however, is not 

reflected in patients with mental 

illnesses. The rate of smoking 

in patients suffering from posttraumatic stress disorder, bipolar 

disorder, major depression, and 

other mental illnesses is twofold to 

fourfold higher than in the general 

population; and among people with 

schizophrenia, smoking rates as high 

as 90 percent have been reported. 

Tobacco use is the leading 

preventable cause of death in the 

United States. The impact of tobacco 

use in terms of morbidity and 

mortality to society is staggering.

Economically, more than $96 

billion of total U.S. healthcare costs 

each year are attributable directly 

to smoking. However, this is well 

below the total cost to society 

because it does not include burn 

care from smoking-related fires, 

perinatal care for low-birthweight 

infants of mothers who smoke, 

and medical care costs associated 

with disease caused by secondhand 

smoke. In addition to healthcare 

costs, the costs of lost productivity 

due to smoking effects are estimated 

at $97 billion per year, bringing 

a conservative estimate of the 

economic burden of smoking to 

more than $193 billion per year.

How Does 

Tobacco Deliver 

Its Effects? 

There are more than 7,000 

chemicals found in the smoke 

of tobacco products. Of these, 

nicotine, first identified in the 

early 1800s, is the primary 

reinforcing component of tobacco. 

Cigarette smoking is the most 

popular method of using tobacco; 

however, many people also use 

smokeless tobacco products, such 

as snuff and chewing tobacco. 

These smokeless products 

also contain nicotine, as well 

as many toxic chemicals.

The cigarette is a very efficient 

and highly engineered drug delivery 

system. By inhaling tobacco smoke, 

the average smoker takes in 1–2 

milligrams of nicotine per cigarette. 

When tobacco is smoked, nicotine 

rapidly reaches peak levels in the 

bloodstream and enters the brain. 

A typical smoker will take 10 puffs 

on a cigarette over a period of 5 

minutes that the cigarette is lit. 

Thus, a person who smokes about 

11⁄2 packs (30 cigarettes) daily gets 

300 “hits” of nicotine to the brain 

each day. In those who typically 

Tobacco 

Addiction

2 NIDA Research Report Series

12th grade

10th grade

8th grade

1995 96 97 98 99 2000 01 02 03 04 05 06 07 08 09 10 11

Source: University of Michigan, 2011 Monitoring the Future Survey. 

5

10

15

20

25

30

35

40

Percent Reporting Use

Trends in Prevalence of Cigarette Use 

for 8th-, 10th-, and 12th-Graders

Percentage of Students Using Cigarettes Over a 30-Day Period, 1995–2011
do not inhale the smoke—such 

as cigar and pipe smokers and 

smokeless tobacco users—nicotine 

is absorbed through the mucosal 

membranes and reaches peak blood 

levels and the brain more slowly.

Immediately after exposure to 

nicotine, there is a “kick” caused 

in part by the drug’s stimulation 

of the adrenal glands and 

resulting discharge of epinephrine 

(adrenaline). The rush of adrenaline 

stimulates the body and causes 

an increase in blood pressure, 

respiration, and heart rate. 

Is Nicotine 

Addictive?

Yes. Most smokers use tobacco 

regularly because they are 

addicted to nicotine. Addiction is 

characterized by compulsive drugseeking and abuse, even in the face 

of negative health consequences. It is 

well-documented that most smokers 

identify tobacco use as harmful 

and express a desire to reduce or 

stop using it, and nearly 35 million 

of them want to quit each year. 

Unfortunately, more than 85 percent 

of those who try to quit on their 

own relapse, most within a week.

Research has shown how 

nicotine acts on the brain to produce 

a number of effects. Of primary 

importance to its addictive nature 

are findings that nicotine activates 

reward pathways—the brain circuitry 

that regulates feelings of pleasure. 

A key brain chemical involved in 

mediating the desire to consume 

drugs is the neurotransmitter 

dopamine, and research has shown 

that nicotine increases levels of 

dopamine in the reward circuits. This 

reaction is similar to that seen with 

other drugs of abuse and is thought 

to underlie the pleasurable sensations 

experienced by many smokers. 

For many tobacco users, long-term 

brain changes induced by continued 

nicotine exposure result in addiction.

Nicotine’s pharmacokinetic 

properties also enhance its abuse 

potential. Cigarette smoking 

produces a rapid distribution of 

nicotine to the brain, with drug 

levels peaking within 10 seconds 

of inhalation. However, the acute 

effects of nicotine dissipate 

quickly, as do the associated 

feelings of reward, which causes 

the smoker to continue dosing to 

maintain the drug’s pleasurable 

effects and prevent withdrawal.

Nicotine withdrawal symptoms 

include irritability, craving, 

depression, anxiety, cognitive and 

attention deficits, sleep disturbances, 

and increased appetite. These 

symptoms may begin within a few 

hours after the last cigarette, quickly 

driving people back to tobacco 

use. Symptoms peak within the 

first few days of smoking cessation 

and usually subside within a few 

weeks. For some people, however, 

symptoms may persist for months.

Although withdrawal is related 

to the pharmacological effects 

of nicotine, many behavioral 

factors can also affect the severity 

of withdrawal symptoms. For 

some people, the feel, smell, and 

sight of a cigarette and the ritual 

of obtaining, handling, lighting, 

and smoking the cigarette are all 

associated with the pleasurable 

effects of smoking and can make 

withdrawal or craving worse. 

Nicotine replacement therapies such 

as gum, patches, and inhalers may 

help alleviate the pharmacological 

aspects of withdrawal; however, 

cravings often persist. Behavioral 

therapies can help smokers 

identify environmental triggers 

of craving so they can employ 

strategies to prevent or circumvent 

these symptoms and urges. 

Tobacco plants

Most smokers 

identify tobacco 

use as harmful and 

express a desire 

to reduce or stop 

using it, and nearly 

35 million want to 

quit each year. 

NIDA Research Report Series 3
Are There Other 

Chemicals That 

May Contribute 

to Tobacco 

Addiction? 

Yes, research is showing that 

nicotine may not be the only 

ingredient in tobacco that affects its 

addictive potential. Using advanced 

neuroimaging technology, scientists 

can see the dramatic effect of 

cigarette smoking on the brain and 

are finding a marked decrease in 

the levels of monoamine oxidase 

(MAO), an important enzyme that 

is responsible for the breakdown 

of dopamine. This change is likely 

caused by some ingredient in 

tobacco smoke other than nicotine, 

because we know that nicotine 

itself does not dramatically alter 

MAO levels. The decrease in two 

forms of MAO (A and B) results 

in higher dopamine levels and may 

be another reason that smokers 

continue to smoke—to sustain the 

high dopamine levels that lead to 

the desire for repeated drug use.

Animal studies by NIDAfunded researchers have shown 

that acetaldehyde, another 

chemical found in tobacco 

smoke, dramatically increases the 

reinforcing properties of nicotine 

and may also contribute to tobacco 

addiction. The investigators further 

report that this effect is age-related: 

adolescent animals display far 

more sensitivity to this reinforcing 

effect, which suggests that the 

brains of adolescents may be more 

vulnerable to tobacco addiction.

What Are 

the Medical 

Consequences 

of Tobacco Use?

Cigarette smoking kills an estimated 

440,000 U.S. citizens each year—

more than alcohol, illegal drug use, 

homicide, suicide, car accidents, 

and AIDS combined. Between 1964 

and 2004, more than 12 million 

Americans died prematurely from 

smoking, and another 25 million U.S. 

smokers alive today will most likely 

die of a smoking-related illness. 

Cigarette smoking harms nearly 

every organ in the body. It has been 

conclusively linked to cataracts and 

pneumonia, and accounts for about 

one-third of all cancer deaths. The 

overall rates of death from cancer 

are twice as high among smokers as 

nonsmokers, with heavy smokers 

having rates that are four times 

greater than those of nonsmokers. 

Foremost among the cancers caused 

by tobacco use is lung cancer—

cigarette smoking has been linked to 

about 90 percent of all cases of lung 

cancer, the number one cancer killer 

of both men and women. Smoking 

is also associated with cancers of the 

mouth, pharynx, larynx, esophagus, 

stomach, pancreas, cervix, kidney, 

bladder, and acute myeloid leukemia. 

In addition to cancer, smoking 

causes lung diseases such as chronic 

bronchitis and emphysema, and 

it has been found to exacerbate 

asthma symptoms in adults and 

children. About 90 percent of all 

deaths from chronic obstructive 

pulmonary diseases are attributable 

to cigarette smoking. It has also 

been well-documented that smoking 

substantially increases the risk of 

heart disease, including stroke, 

Nicotine replacement 

therapies such as gum, 

patches, and inhalers 

may help alleviate 

the pharmacological 

aspects of withdrawal.

Using advanced neuroimaging technology, scientists can see the dramatic effect of 

cigarette smoking on the brain and body and are finding a marked decrease in the 

levels of monoamine oxidase (MAO), an important enzyme that is responsible for 

the breakdown of dopamine. (Source: Fowler et al., 2003)

4 NIDA Research Report Series
heart attack, vascular disease, 

and aneurysm. Smoking causes 

coronary heart disease, the leading 

cause of death in the United States: 

cigarette smokers are 2–4 times 

more likely to develop coronary 

heart disease than nonsmokers.

Exposure to high doses of 

nicotine, such as those found in 

some insecticide sprays, can be 

extremely toxic as well, causing 

vomiting, tremors, convulsions, 

and death. In fact, one drop of pure 

nicotine can kill a person. Nicotine 

poisoning has been reported 

from accidental ingestion of 

insecticides by adults and ingestion 

of tobacco products by children 

and pets. Death usually results in 

a few minutes from respiratory 

failure caused by paralysis.

Although we often think of 

medical consequences that result 

from direct use of tobacco products, 

passive or secondary smoke also 

increases the risk for many diseases. 

Environmental tobacco smoke 

is a major source of indoor air 

contaminants; secondhand smoke 

is estimated to cause approximately 

3,000 lung cancer deaths per year 

among nonsmokers and contributes 

to more than 35,000 deaths related 

to cardiovascular disease. Exposure 

to tobacco smoke in the home is 

also a risk factor for new cases 

Sticky, brown tar coats the 

lungs of tobacco smokers. 

Along with thousands of 

other damaging chemicals, 

tar can lead to lung cancer 

and acute respiratory 

diseases.

NIDA Research Report Series 5

Are There 

Safe Tobacco 

Products?

The adverse health effects of 

tobacco use are well known, 

yet many people do not want to 

quit or have difficulty quitting. 

As a result, there has been a 

recent surge in the development 

of tobacco products that claim 

to reduce exposure to harmful 

tobacco constituents or to have 

fewer health risks than conventional products. These “potentially reduced exposure products” 

(PREPs), which include cigarettes 

and smokeless tobacco (e.g., 

snuff, tobacco lozenges), have not 

yet been evaluated sufficiently 

to determine whether they are 

indeed associated with reduced 

risk of disease. Recent studies 

indicate that the levels of carcinogens in these PREPs range from 

relatively low to comparable to 

conventional tobacco products. 

These studies conclude that 

medicinal nicotine (found in the 

nicotine patch and gum) is a safer 

alternative than these modified 

tobacco products.
and increased severity of childhood 

asthma. Additionally, dropped 

cigarettes are the leading cause of 

residential fire fatalities, leading to 

more than 1,000 deaths each year.

Smoking and 

Pregnancy—

What Are 

the Risks?

In the United States, it is estimated 

that about 16 percent of pregnant 

women smoke during their 

pregnancies. Carbon monoxide 

and nicotine from tobacco smoke 

may interfere with the oxygen 

supply to the fetus. Nicotine also 

readily crosses the placenta, and 

concentrations in the fetus can 

be as much as 15 percent higher 

than maternal levels. Nicotine 

concentrates in fetal blood, 

amniotic fluid, and breast milk. 

Combined, these factors can have 

severe consequences for the fetuses 

and infants of smoking mothers. 

Smoking during pregnancy caused 

an estimated 910 infant deaths 

annually from 1997 through 2001, 

and neonatal care costs related 

to smoking are estimated to be 

more than $350 million per year.

The adverse effects of smoking 

during pregnancy can include fetal 

growth retardation and decreased 

birthweight. The decreased 

birthweights seen in infants of 

mothers who smoke reflect a 

dose-dependent relationship—

the more the woman smokes 

during pregnancy, the greater the 

reduction of infant birthweight. 

These newborns also display signs 

of stress and drug withdrawal 

consistent with what has been 

reported in infants exposed to other 

drugs. In some cases, smoking 

during pregnancy may be associated 

with spontaneous abortions and 

sudden infant death syndrome 

(SIDS), as well as learning and 

behavioral problems and an 

increased risk of obesity in children. 

There is clear evidence of high rates of psychiatric comorbidity, including other substance abuse, 

among adolescents and adults who smoke. For 

example, it has been estimated that individuals with 

psychiatric disorders purchase approximately 44 

percent of all cigarettes sold in the United States, 

which undoubtedly contributes to the disproportionate rates of morbidity and mortality in these populations. In addition, studies have shown that as many 

as 80 percent of alcoholics smoke regularly, and that 

a majority of them will die of smoking-related, rather 

than alcohol-related, disease. 

In young smokers, the behavior appears to be 

strongly associated with increased risk for a variety 

of mental disorders. In some cases—such as with 

conduct disorders and attention-deficit hyperactivity 

disorder—these disorders may precede the onset of 

smoking, while in others—such as with substance 

abuse—the disorders may emerge later in life. 

Whether daily smoking among boys and girls is the 

result or the cause of a manifest psychiatric condition, it is troubling that so very few adolescents have 

their nicotine dependence diagnosed or properly 

treated. Preventing the early onset of smoking and 

treating its young victims are critical primary-care priorities, the fulfillment of which could have a dramatic 

impact on our ability to prevent or better address a 

wide range of mental disorders throughout life. 

Among adults, the rate of major depressive episodes is highest in nicotine-dependent individuals, 

lower in nondependent current smokers, and lowest 

in those who quit or never started smoking. Furthermore, there is evidence showing that, for those who 

have had more than one episode, smoking cessation 

may increase the likelihood of a new major depressive episode. Adult tobacco use also increases 

risk for the later development of anxiety disorders, 

which may be associated with an increased severity 

of withdrawal symptoms during smoking cessation 

therapy. But the most extensive comorbidity overlap 

is likely the one that exists between smoking and 

schizophrenia, since, in clinical samples, the rate of 

smoking in patients with schizophrenia has ranged 

as high as 90 percent.

Tobacco Use and Comorbidity

6 NIDA Research Report Series
Smoking and Adolescence

In 2010, about 2.6 million American adolescents (aged 12–17) reported 

using a tobacco product in the month prior to the survey. In that same 

year, it was found that nearly 60 percent of new smokers were under 

the age of 18 when they first smoked a cigarette. Of smokers under age 

18, more than 6 million will likely die prematurely from a smoking-related 

disease.

Tobacco use in teens is not only the result of psychosocial influences, 

such as peer pressure; recent research suggests that there may be 

biological reasons for this period of increased vulnerability. There is 

some evidence that intermittent smoking can result in the development 

of tobacco addiction in some teens. Animal models of teen smoking 

provide additional evidence of an increased vulnerability. Adolescent rats 

are more susceptible to the reinforcing effects of nicotine than adult 

rats, and take more nicotine when it is available than do adult animals.

Adolescents may also be more sensitive to the reinforcing effects of 

nicotine in combination with other chemicals found in cigarettes, thus 

increasing susceptibility to tobacco addiction. As mentioned earlier, 

acetaldehyde increases nicotine’s addictive properties in adolescent, 

but not adult, animals. A recent study also suggests that specific genes 

may increase risk for addiction among people who begin smoking 

during adolescence. NIDA continues to actively support research aimed 

at increasing our understanding of why and how adolescents become 

addicted, and to develop prevention and treatment strategies to meet 

their specific needs.

In addition, smoking more than one 

pack a day during pregnancy nearly 

doubles the risk that the affected 

child will become addicted to 

tobacco if that child starts smoking.

Are There Gender 

Differences 

in Tobacco 

Smoking?

Several avenues of research now 

indicate that men and women 

differ in their smoking behaviors. 

For instance, women smoke fewer 

cigarettes per day, tend to use 

cigarettes with lower nicotine 

content, and do not inhale as 

deeply as men. However, it is 

unclear whether this is due to 

differences in sensitivity to nicotine 

or other factors that affect women 

Large-scale smoking 

cessation trials show 

that women are 

less likely to initiate 

quitting and may be 

more likely to relapse 

if they do quit. 

NIDA Research Report Series 7
differently, such as social factors or 

the sensory aspects of smoking.

The number of smokers in the 

United States declined in the 1970s 

and 1980s, remained relatively stable 

throughout the 1990s, and declined 

further through the early 2000s. 

Because this decline in smoking was 

greater among men than women, 

the prevalence of smoking is only 

slightly higher for men today than it 

is for women. Several factors appear 

to be contributing to this narrowing 

gender gap, including women 

being less likely than men to quit.

Large-scale smoking cessation 

trials show that women are less 

likely to initiate quitting and may 

be more likely to relapse if they do 

quit. In cessation programs using 

nicotine replacement methods, such 

as the patch or gum, the nicotine 

does not seem to reduce craving as 

effectively for women as for men. 

Other factors that may contribute 

to women’s difficulty with quitting 

are that withdrawal may be more 

intense for women or that women are 

more concerned about weight gain.

Although postcessation weight 

gain is typically modest (about 

5–10 pounds), concerns about this 

may be an obstacle to treatment 

success. In fact, NIDA research has 

found that when women’s weight 

concerns were addressed during 

cognitive-behavioral therapy, 

they were more successful at 

quitting than women who were in a 

program designed only to attenuate 

postcessation weight gain. Other 

NIDA researchers have found that 

medications used for smoking 

cessation, such as bupropion and 

naltrexone, can also attenuate 

postcessation weight gain and could 

become an additional strategy for 

enhancing treatment success. 

It is important for treatment 

professionals to be aware that 

standard regimens may have to be 

adjusted to compensate for gender 

differences in nicotine sensitivity 

and in other related factors that 

contribute to continued smoking.

Are There 

Effective 

Treatments 

for Tobacco 

Addiction?

Yes, extensive research has 

shown that treatments for tobacco 

addiction do work. Although some 

smokers can quit without help, 

many individuals need assistance 

with quitting. This is particularly 

important because smoking cessation 

can have immediate health benefits. 

For example, within 24 hours of 

quitting, blood pressure and chances 

of heart attack decrease. Long-term 

benefits of smoking cessation include 

decreased risk of stroke, lung and 

other cancers, and coronary heart 

disease. A 35-year-old man who quits 

smoking will, on average, increase 

his life expectancy by 5 years.

Nicotine Replacement 

Treatments

Nicotine replacement therapies 

(NRTs), such as nicotine gum and 

the transdermal nicotine patch, were 

the first pharmacological treatments 

approved by the Food and Drug 

Administration (FDA) for use in 

smoking cessation therapy. NRTs are 

used (in conjunction with behavioral 

support) to relieve withdrawal 

symptoms—they produce less 

severe physiological alterations than 

tobacco-based systems and generally 

provide users with lower overall 

nicotine levels than they receive 

with tobacco. An added benefit is 

that these forms of nicotine have 

little abuse potential since they do 

not produce the pleasurable effects 

of tobacco products, nor do they 

contain the carcinogens and gases 

associated with tobacco smoke. 

Behavioral treatments, even beyond 

what is recommended on packaging 

labels, have been shown to enhance 

the effectiveness of NRTs and 

improve long-term outcomes.

The FDA’s approval of nicotine 

gum in 1984 marked the availability 

(by prescription) of the first NRT 

on the U.S. market. In 1996, the 

FDA approved Nicorette gum for 

over-the-counter (OTC) sales. 

Whereas nicotine gum provides 

Smoking cessation can 

have immediate health 

benefits. For example, 

within 24 hours of 

quitting, blood pressure 

and chances of heart 

attack decrease. 

8 NIDA Research Report Series
some smokers with the desired 

control over dose and the ability to 

relieve cravings, others are unable 

to tolerate the taste and chewing 

demands. In 1991 and 1992, the FDA 

approved four transdermal nicotine 

patches, two of which became OTC 

products in 1996. In 1996 a nicotine 

nasal spray, and in 1998 a nicotine 

inhaler, also became available 

by prescription, thus meeting the 

needs of many additional tobacco 

users. All the NRT products—

gum, patch, spray, and inhaler—

appear to be equally effective.

Additional Medications

Although the primary focus of 

pharmacological treatments for 

tobacco addiction has been nicotine 

replacement, other treatments are 

also available. For example, the 

antidepressant bupropion was 

approved by the FDA in 1997 to 

help people quit smoking and is 

marketed as Zyban. Varenicline 

tartrate (Chantix) is a medication that 

recently received FDA approval for 

smoking cessation. This medication, 

which acts at the sites in the brain 

affected by nicotine, may help 

people quit by easing withdrawal 

symptoms and blocking the effects of 

nicotine if people resume smoking.

Several other non-nicotine 

medications are being 

investigated for the treatment 

of tobacco addiction, including 

other antidepressants and an 

antihypertensive medication. 

Scientists are also investigating 

the potential of a vaccine that 

targets nicotine for use in relapse 

prevention. The nicotine vaccine is 

designed to stimulate the production 

of antibodies that would block access 

of nicotine to the brain and prevent 

nicotine’s reinforcing effects.

Behavioral Treatments

Behavioral interventions play an 

integral role in smoking cessation 

treatment, either in conjunction 

with medication or alone. A variety 

of methods can assist smokers 

with quitting, ranging from selfhelp materials to individual 

cognitive-behavioral therapy. These 

interventions teach individuals 

to recognize high-risk smoking 

situations, develop alternative coping 

strategies, manage stress, improve 

problemsolving skills, and increase 

social support. Research has also 

shown that the more therapy is 

tailored to a person’s situation, the 

greater the chances are for success. 

Traditionally, behavioral 

approaches were developed and 

delivered through formal settings, 

such as smoking cessation clinics 

and community and public health 

settings. Over the past decade, 

however, researchers have been 

adapting these approaches for mail, 

telephone, and Internet formats, 

which can be more acceptable 

and accessible to smokers who 

are trying to quit. In 2004, the 

U.S. Department of Health and 

Human Services (HHS) established 

a national toll-free number, 

800-QUIT-NOW (800-784-8669), 

to serve as a single access point for 

smokers seeking information and 

assistance in quitting. Callers to the 

number are routed to their State’s 

smoking cessation quitline or, in 

States that have not established 

quitlines, to one maintained by 

the National Cancer Institute. In 

addition, a new HHS Web site 

(www.smokefree.gov) offers 

NIDA Research Report Series 9

Twin studies indicate 

that approximately 

40–70 percent of 

a person’s risk of 

becoming addicted 

to nicotine depends 

on his or her genes. 
online advice and downloadable 

information to make cessation easier. 

Quitting smoking can be difficult. 

People can be helped during the 

time an intervention is delivered; 

however, most intervention programs 

are short-term (1–3 months). 

Within 6 months, 75–80 percent 

of people who try to quit smoking 

relapse. Research has now shown 

that extending treatment beyond 

the typical duration of a smoking 

cessation program can produce quit 

rates as high as 50 percent at 1 year.

New Frontiers 

in Tobacco 

Research

If so many smokers want to 

quit, why are few able to do so 

successfully? To address this 

question, scientists are increasingly 

focusing on the powerful role 

of genetics in addiction. Twin 

studies indicate that approximately 

40–70 percent of a person’s risk 

of becoming addicted to nicotine 

depends on his or her genes. 

Although complex diseases like 

addiction involve large numbers 

of genes interacting with a wide 

variety of environmental factors, 

the contribution of a particular 

gene can be substantial. 

Genetic variants associated with 

nicotine metabolism, for example, 

have been shown to influence how 

people smoke. Slow metabolizers 

smoke fewer cigarettes per day and 

have a higher likelihood of quitting, 

and there is greater abstinence 

among individuals receiving 

nicotine patch therapy. A recent 

NIDA-funded study identified a 

variant in the gene for a nicotinic 

receptor subunit that doubled the 

risk for nicotine addiction among 

smokers. A subsequent study 

found that this gene variant also 

increased susceptibility to the 

severe health consequences of 

smoking, including lung cancer and 

peripheral arterial disease. NIDA 

is currently supporting large-scale 

genome-wide association studies 

to uncover additional genetic 

risk factors in order to better 

understand tobacco addiction and 

its adverse effects on health. 

In addition to predicting an 

individual’s risk for nicotine 

addiction, genetic markers 

can also help predict whether 

medications (like bupropion) will 

effectively help a smoker quit. 

This takes root in the emerging 

field of pharmacogenomics, 

which investigates how genes 

influence a patient’s response to 

drugs and medications. In the 

future, genetic screening could 

help clinicians select treatments, 

adjust dosages, and avoid or 

minimize adverse reactions, 

tailoring smoking cessation 

therapies to an individual’s 

unique genetic inheritance.

Glossary

Addiction: A chronic, relapsing 

disease characterized by compulsive 

drug-seeking and abuse despite 

adverse consequences. It is 

associated with long-lasting changes 

in the brain. 

Adrenal glands: Glands located 

above each kidney that secrete 

hormones, e.g., adrenaline.

Carcinogen: Any substance that 

causes cancer. 

Craving: A powerful, often 

uncontrollable desire for drugs.

Dopamine: A neurotransmitter 

present in regions of the brain 

that regulate movement, emotion, 

motivation, and feelings of pleasure.

Emphysema: A lung disease in 

which tissue deterioration results in 

increased air retention and reduced 

exchange of gases. The result is 

difficulty breathing and shortness of 

breath. 

Neurotransmitter: A chemical that 

acts as a messenger to carry signals 

or information from one nerve cell to 

another. 

Nicotine: An alkaloid derived 

from the tobacco plant that is 

primarily responsible for smoking’s 

psychoactive and addictive effects.

Pharmacokinetics: The pattern of 

absorption, distribution, and excretion 

of a drug over time.

Tobacco: A plant widely cultivated for 

its leaves, which are used primarily 

for smoking; the N. tabacum species 

is the major source of tobacco 

products.

Withdrawal: A variety of symptoms 

that occur after chronic use of an 

addictive drug is reduced or stopped.

10 NIDA Research Report Series
Adams, E.K.; Miller, V.P.; Ernst, C.; 

Nishimura, B.K.; Melvin, C.; and 

Merritt, R. Neonatal health care 

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References

NIDA Research Report Series 11
NIH Publication Number 12-4342 

Printed July 1998, Reprinted August 2001, Revised July 2006, 

Revised June 2009, Revised July 2012

Feel free to reprint this publication.

To learn more about tobacco and 

other drugs of abuse, or to order 

materials on these topics free of 

charge in English or Spanish, 

visit the NIDA Web site at www.

drugabuse.gov or contact the 

DrugPubs Research Dissemination 

Center at 877-NIDA-NIH 

(877-643-2644; TTY/TDD: 

240-645-0228).

Where Can I Get More Scientific Information on 

Tobacco Addiction?

What’s on the NIDA Web Site

• Information on Drugs of 

Abuse and Related Health 

Consequences

• NIDA Publications, News, and 

Events

• Resources for Health Care 

Professionals

• Funding Information

• International Activities

NIDA Web Sites

NIDA Home Page:

http://www.drugabuse.gov

NIDA Drug Facts:

http://www.drugabuse.gov/

publications/term/160/DrugFacts

Easy-to-Read Drug Facts:

http://easyread.drugabuse.gov

NIDA/SAMHSA Blending 

Initiative: http://www.drugabuse.

gov/blending-initiative

For Physician Information

www.drugabuse.gov/nidamed

Other Web Sites

Information on tobacco 

addiction is also available 

through these Web sites:

• Centers for Disease Control 

and Prevention: 

www.cdc.gov/tobacco

• National Cancer Institute: 

www.cancer.gov

• U.S. Department of Health 

and Human Services: 

www.smokefree.gov

• Substance Abuse and Mental 

Health Services Administration 

Health Information Network: 

www.samhsa.gov/shin

• Office of the Surgeon General: 

http://www.surgeongeneral.

gov/initiatives/tobacco

• Society for Research on 

Nicotine and Tobacco: 

www.srnt.org

• The Robert Wood Johnson 

Foundation: 

www.rwjf.org

• Join Together Online: 

www.quitnet.com

• American Legacy Foundation: 

www.americanlegacy.org