cigarette break

If you know something’s bad for you, why can’t you just stop?

For many decades, it has been widely known that smoking is extremely harmful to our health, yet it continues to be a habit that is very difficult to quit or even control. And smoking treatment products and programs have become a billion dollar industry that shows no sign of slowing growth. NIH scientists have been searching for answers. They’re studying what happens in our brains as habits form. They’re finding clues to why bad habits, once established, turn into addiction and are so difficult to kick. And they’re developing strategies to help us make the changes we’d like to make. On the following pages, we’ll take a broad look at the impact of smoking on society as whole, specific health effects of smoking on the individual smoker, why so many people fail at quitting, the latest research on nicotine dependence, and how you can help advance our body of knowledge on smoking treatment.


Cigarette smoking, which remains prevalent in about 20% of Americans, is the most common preventable cause of death and disease in the United States, accounting for about 1 of every 5 deaths.

  • Of these, approximately 160,000 are due to cancers, 130,000 to cardiovascular disease and another 100,000 to respiratory diseases.
  • More deaths are caused each year by tobacco use than by all deaths from human HIV, illegal drug and alcohol use, motor vehicle injuries, suicides, and murders combined.
  • On average, adults who smoke cigarettes die 14 years earlier than nonsmokers.
  • Based on current smoking patterns, about 25 million Americans alive today will die prematurely from smoking-related illnesses, including 5 million people younger than 18.
  • More recently, research has shown that chronic smoking is also associated with poorer neurocognitive functioning.

broken cigarettes


When you hear about the dangers of cigarette smoking, the first thing we think about is the threat to our lungs. While it’s clear that there is a direct link between smoking and conditions such as lung cancer, chronic bronchitis, and emphysema, there is also conclusive proof that smoking increases the risk of harm to nearly every part of your body.

Hearing Loss
Smoking reduces the oxygen supply to the cochlea, an organ in the inner ear, which may result in permanent hearing damage.

Reduced Vision and Blindness
Nicotine from cigarettes restricts the production of a chemical necessary for you to see at night. And smoking increases the risk of developing cataracts and macular degeneration, both of which can lead to blindness.

Oral Disease
In addition to having greater risk of mouth sores, ulcers, and gum disease, smokers are more likely to have cavities and lose their teeth at a younger age.

Weakened Immune System
Cigarette smoke contains high levels of tar and other chemicals, which can make your immune system less effective at fighting off infections.

Muscle Deterioration
When you smoke, less blood and oxygen flow to your muscles, making it harder to build muscle. The lack of oxygen also makes muscles tire more easily.

Bone Degeneration
Ingredients in cigarette smoke disrupt the natural cycle of bone health, so your body is less able to form healthy new bone tissue. Compared to non-smokers, smokers have a higher risk of bone fractures, and their broken bones take longer to heal.

smashed cigarettes


In a word, nicotine.

Cigarettes and other forms of tobacco—including cigars, pipe tobacco, snuff, and chewing tobacco—contain this addictive drug. Nicotine is readily absorbed into the bloodstream when a tobacco product is chewed, inhaled, or smoked. A typical smoker will take 10 or more puffs on a cigarette over the period of about 5 minutes that the cigarette is lit. Thus, a person who smokes about 1 pack (25 cigarettes) daily gets at least 250 “hits” of nicotine each day. Upon entering the bloodstream, nicotine immediately stimulates the adrenal glands to release the hormone epinephrine (adrenaline). Epinephrine stimulates the central nervous system and increases blood pressure, respiration, and heart rate. Similar to other addictive drugs like cocaine and heroin, nicotine increases levels of the neurotransmitter dopamine, which affects the brain pathways that control reward and pleasure. For many tobacco users, long-term brain changes induced by continued nicotine exposure result in addiction—a condition of compulsive drug seeking and use, even in the face of negative consequences. Studies suggest that additional compounds in tobacco smoke, such as acetaldehyde, may enhance nicotine’s effects on the brain. When an addicted smoker tries to quit, he or she experiences withdrawal symptoms that often include irritability, attention difficulties, sleep disturbances, and increased appetite. It’s no wonder that smokers continue to smoke in order to avoid these problems.


Most smokers understand the negative health consequences of continued smoking—70% report that they want to quit and 44% state that they try to quit each year. Despite this, roughly 80% of smokers who attempt to quit relapse within the first month, and a further 95% within 6 months. Even when assisted with current treatments such as nicotine replacement patches, only 30% of people manage to successfully maintain abstinence. The lack of effective treatments for nicotine addiction stems in part from the poor understanding of the ‘addicted’ brain in general, and the complex actions of nicotine on the brain, as well as changes in the brain and its circuitry associated with prolonged exposure to nicotine. In order to develop better treatment programs, we need to learn more about the brain mechanisms that are responsible for addiction, and how they change as a person transitions from a smoker to a non-smoker.


The National Institutes of Health (NIH) is dedicated to acquiring new knowledge to help prevent, diagnose, and treat disease and disability. As such, it is keenly interested in nicotine dependence, and is engaged in research aimed at developing a deeper understanding of this problem that can lead to new and hopefully more effective treatments. As part of our smoking cessation treatment research, the NIH is now undertaking studies, which aim to develop a greater understanding of nicotine dependence and ultimately develop more effective ways to help people quit smoking” With the participation of current and former smokers, this research, conveniently located on the Bayview Johns Hopkins Campus, may help:

  • Explain what makes a person likely to become addicted to nicotine.
  • Identify what happens in the brain to trigger withdrawal symptoms.
  • Determine the role that genetic differences play in smoking and quitting.
  • Understand the effects of e-cigarettes on the brain.
  • Predict who will be successful in quitting.
  • Improve and tailor treatments in the future.

Dr. Stein
Elliot A. Stein, Ph.D.

Dr. Elliot Stein is Chief of the Neuroimaging Research Branch at the National Institute on Drug Abuse Intramural Research Program. Prior to coming to NIDA in 2002, he was Professor of Psychiatry, Pharmacology, and Neurobiology at the Medical College of Wisconsin. He received his Ph.D. from the University of Maryland School of Medicine and completed a post-doctoral fellowship at the California Institute of Technology with James Olds, a pioneer in brain reward systems. His research program aims to 1) define those neuronal systems and circuits mediating the actions of abused drugs, 2) determine CNS sites and mechanisms responsible for mediating drug craving and reinforcement, and 3) understand how drugs interact with specific cognitive processes to alter behavior. Most recently he has been examining the influence of various genetic polymorphisms on imaging biomarkers of addiction.


If you are a current or former smoker, you could help advance the NIH research—really. Simply return to the website and follow the steps in “How do I sign up?” Or call 1-866-START-NOW (1-866-782-7866) Monday through Friday, 8:30 am to 6:30 pm to have a confidential screening to help determine if you are eligible to take part in the research. Participants are paid for time and travel (between $380 and $1,700, depending on the study you are best qualified for). Individualized counseling and medication or e-cigarettes are available at no cost to those seeking to quit smoking. The research is conducted at: The National Institutes of Health, Smoking Treatment Research Center - Baltimore 251 Bayview Boulevard, Suite 200 Baltimore, MD 21224 (located on the Johns Hopkins Bayview Campus)