Nicotine and related disorders
Nicotine disorders are caused by the main psychoactive ingredient in tobacco. Nicotine is a physically and psychologically addictive drug. It is the most influential dependence-producing drug in the United States and worldwide, and its use is associated with many serious health risks.
Nicotine is the most addictive and psychoactive chemical in tobacco, a plant native to the New World. Early European explorers learned to smoke its leaves from indigenous peoples who had been using tobacco for hundreds of years. They took tobacco back to Europe, where it became immensely popular. Tobacco became a major source of income for the American colonies and later for the United States. Advances in cigarette-making technology caused a boom in cigarette smoking in the early 1900s. Before the early twentieth century, most people who smoked had used pipes, cigars, or chewing tobacco.
In the 1950s researchers began to link cigarette smoking to certain respiratory diseases and cancers. In 1964 the Surgeon General of the United States issued the first health report on smoking. Cigarette smoking peaked in the United States in the 1970s, then began to decline as health concerns about tobacco increased. In 1971 cigarette advertising was banned from television, although tobacco products continue to be heavily advertised in other media even today. By 1998, it was estimated that 25% of Americans (about 60 million people) were active smokers, 25% were former smokers, and the remaining half have never smoked. About 85% of active smokers are addicted to nicotine.
Pure nicotine is a colorless liquid that turns brown and smells like tobacco when exposed to air. Nicotine can be absorbed through the skin, the lining of the mouth and nose, and the moist tissues lining the lungs. Cigarettes are the most efficient nicotine delivery system. Once tobacco smoke is inhaled, nicotine reaches the brainin less than 15 seconds. Since people who smoke pipes and cigars do not inhale, they absorb nicotine more slowly. Nicotine in chewing tobacco and snuff is absorbed through the mucous membranes lining the mouth and nasal passages. In 2002 a new smokeless tobacco product was test-marketed in the United States. Called Ariva, it is compressed tobacco powder about the size of a vitamin pill that is placed between the cheek and gum until it dissolves completely. The nicotine it contains is also absorbed through the mucous membranes of the mouth.
How nicotine works
Nicotine is the main addictive drug among the 4,000 compounds found in tobacco smoke. Such other substances in smoke as tar and carbon monoxide present documented health hazards, but they are not addictive and do not cause cravings or withdrawal symptoms to the extent that nicotine does.
Nicotine is both a stimulant and a sedative. It is a psychoactive drug, meaning that it works in the brain, alters brain chemistry, and changes mood. Once tobacco smoke is inhaled, nicotine passes rapidly through the linings of the lungs and into the blood. It quickly circulates to the brain where it indirectly increases the supply of dopamine, a chemical in the brain that affects mood. Dopamine is normally released in response to pleasurable sensations. Nicotine, like cocaine or heroin, artificially stimulates the release of dopamine. This release accounts for the pleasurable sensation that most smokers feel almost as soon as they light up a cigarette. Nicotine also decreases anger and increases the efficiency of a person's performance on long, dull tasks.
At the same time nicotine is affecting the brain, it also stimulates the adrenal glands. The adrenal glands are small, pea-sized pieces of tissue located above each kidney. They produce several hormones, one of which is epinephrine, also called adrenaline. Under normal circumstances, adrenaline is released in response to stressor a perceived threat. It is sometimes called the "fight or flight" hormone, because it prepares the body for action. When adrenaline is released, blood pressure, heart rate, blood flow, and oxygen use increase. Glucose, a simple form of sugar used by the body, floods the body to provide extra energy to muscles. The overall effect of the release of these hormones is strain on the cardiovascular (heart and blood vessels) system. Stressed this way many
Most people begin smoking between the ages of 12 and 20. Surprisingly few people start smoking as adults over 21. Adolescents who smoke tend to begin as casual smokers, out of rebelliousness or a need for social acceptance. Dependence on nicotine develops rapidly, however; one study suggests that 85–90% of adolescents who smoke four or more cigarettes become regular smokers. Nicotine is so addictive that being tobacco-free soon feels uncomfortable. In addition, smokers quickly develop tolerance to nicotine. Tolerance is a condition that occurs when the body needs a larger and larger dose of a substance to produce the same effect. For smokers, tolerance to nicotine means more frequent and more rapid smoking. Soon most smokers develop physical withdrawal symptoms when they try to stop smoking. Users of other forms of tobacco experience the same effects; however, the delivery of nicotine is slower and the effects may not be as pronounced.
In addition to the physical dependence caused by the actions of nicotine on the brain, there is a strong psychological component to the dependency of most users of tobacco products, especially cigarette smokers. Most people who start smoking or using smokeless tobacco products do so because of social factors. These include:
- the desire to fit in with peers
- acceptance by family members who use tobacco
- the association of tobacco products with maturity and sophistication
- positive response to tobacco advertising
Such personal factors as mental illness (depression, anxiety, schizophrenia, or alcoholism); the need to reduce stress and anxiety; or a desire to avoid weight gain also influence people to start smoking. Once smoking has become a habit, whether physical addictionoccurs or not, psychological factors play a significant role in continuing to smoke. People who want to stop smoking may be discouraged from doing so because:
- They live or work with people who smoke and who are not supportive of their quitting.
- They believe they are incapable of quitting.
- They perceive no health benefits to quitting.
- They have tried to quit before and failed.
- They associate cigarettes with specific pleasurable activities or social situations that they are not willing to give up.
- They fear gaining weight. Successful smoking cessation programs must treat both the physical and psychological aspects of nicotine addiction.
The American Psychiatric Association first recognized nicotine dependence and nicotine withdrawal as serious psychological problems in 1980. Today nicotine is considered an addictive drug, although a common and legalized one.
Studies show that three-quarters of smokers try to quit, but only about 5–10% are eventually successful. Even those who succeed often make between five and ten attempts to quit before finally succeeding. Symptoms of nicotine withdrawal occur in about half the smokers trying
As former smokers can attest, the combination of physiological and psychological factors make withdrawal from nicotine very difficult. Symptoms of nicotine withdrawal include:
- increased anger or frustration
- sleep disturbances
- inability to concentrate
- increased appetite or desire for sweets
- constant thoughts about smoking
- cravings for cigarettes
- decreased heart rate
Withdrawal symptoms are usually more pronounced in smokers than in those who use smokeless tobacco products, and heavy smokers tend to have more symptoms than light smokers when they try to stop smoking. People with depression, schizophrenia, alcoholism, or mood disorders find it especially difficult to quit, as nicotine offers temporary relief for some of the symptoms of these disorders.
Symptoms of nicotine withdrawal begin rapidly and peak within one to three days. Because of this rapid onset of withdrawal symptoms, only about 30% of people who try to quit smoking remain tobacco-free for even two days. Withdrawal symptoms generally last three to four weeks, but a significant number of smokers have withdrawal symptoms lasting longer than one month. Some people have strong cravings for tobacco that last for months, even though the physical addiction to nicotine is gone. These cravings often occur in social settings in which the person formerly smoked, such as at a bar or party, or after sex. Researchers believe that much of this extended craving is psychological.
About 60 million Americans smoke cigarettes, cigars, and pipes; and about six million more use smokeless tobacco. Worldwide, there are more than a billion smokers. Although the prevalence of smoking has gradually decreased in the United States and many other industrialized countries since the 1970s, the use of tobacco products is rapidly increasing in the developing nations of Africa and Asia. Use of tobacco products in developing countries is of particular concern, because these countries often lack adequate health care resources to treat smoking-related diseases, let alone support smoking cessation programs.
In the past, the number of American men who smoked outnumbered women, but by 2000, the rate of smoking was almost the same for these two groups— about 35% of the population. Men in the United States greatly outnumber women, however, in the use of smokeless tobacco (14% to 1%). In developing countries, male smokers outnumber women smokers by a margin of eight to one. People who smoke tend to have lower levels of income and formal education than those who don't. About half the patients diagnosed with psychiatric problems are smokers, while more than three-quarters of those who abuse other substances also smoke.
In 2001, the most recent year for which statistics are available, smoking among high school students decreased. Daily use of cigarettes among eighth graders decreased from 7.4% to 5.5% and among tenth graders from 14% to 12.2%—both significant declines. The rate of smokeless tobacco usage stayed constant at about 4% of eighth graders and 7% of tenth graders, almost all of whom were boys. Smoking among women with less than a high school education increased, however. Although African American men overall have the highest rate of smoking in the United States population, smoking among African American high school students has decreased significantly. Only about 19% of African American high
Recent research suggests that there may be a genetic component to nicotine dependence, just as there is for alcohol dependence. Studies show that girls (but not boys) whose mothers smoked during pregnancy are four times more likely to smoke than those whose mothers were tobacco-free during pregnancy. Other research suggests that the absence of a certain enzyme in the body protects the body against nicotine dependence.
Smokers usually self-diagnose their nicotine dependence and nicotine withdrawal. Such questionnaires as the Fagerstrom Test for Nicotine Dependence (FTND), a short six-item assessment of cigarette use, help to determine the level of tobacco dependence. Physicians and mental health professionals are less concerned with diagnosis, which is usually straightforward, than with determining the physical and psychological factors in each patient that must be addressed for successful smoking cessation.
Most smokers want to quit; over 75% have tried to stop at least once. Each year, over 40% of smokers make at least one attempt to quit. Many people try a dozen times before they are successful in finding the right combination of medications, therapies, and support to achieve success. Even with repeated attempts, however, only half of all smokers are able to stop smoking completely and eliminate their dependence on nicotine.
Most people do not suddenly wake up one morning and decide to stop smoking. Instead, they go through several preparatory stages before taking action. First is the precontemplation stage, in which the smoker doesnçt even think about quitting. Precontemplation is followed by the contemplation stage, in which the smoker thinks about quitting, but takes no action. Contemplation eventually turns to preparation, often when counselors or family members encourage or urge the smoker to quit. Now the smoker starts making plans to quit in the near future. Finally the smoker arrives at the point of taking action.
Having decided to stop smoking, a person has many choices of programs and approaches. When mental health professionals are involved in smoking cessation efforts, one of their first jobs is to identify the physical and psychological factors that keep the person smoking. This identification helps to direct the smoker to the most appropriate type of program. Assessment examines the frequency of the person's smoking, his or her social and emotional attachment to cigarettes, commitment to change, available support system, and barriers to change. These conditions vary from person to person, which is why some smoking cessation programs work for one person and not another.
Before 1984, there were no medications to help smokers quit. In that year, a nicotine chewing gum (Nicorette) was approved by the United States Food and Drug Administration (FDA) as a prescription drug for smoking cessation. In 1996 it became available without prescription. Nicorette was the first of several medications that are used for nicotine replacement therapy, intended to gradually reduce nicotine dependence in order to prevent or reduce withdrawal symptoms. This approach, called tapering, is used in withdrawal of other addictive drugs.
About 15% of people using nicotine gum are able to stop smoking permanently. This rate is about three times higher than for people who simply go "cold turkey" and stop smoking without any assistance. Nicotine gum comes in two strengths. As it is chewed, nicotine is released and absorbed through the lining of the mouth. Over a six- to 12-week period, the amount and strength of gum chewed is decreased, until the smoker is weaned away from his or her dependence on nicotine. Chewing gum may not be pleasant or socially acceptable to some people, and cannot be used by people who have diseases of the jaw. In addition, some people report that the gum makes them feel queasy.
The nicotine transdermal patches have been available without prescription since 1996. They are marketed under several brand names, including Habitrol, Nicoderm, NicoDerm CQ, Prostep and Nicotrol. All but Nicotrol are 24-hour patches. Nicotrol is a 16-hour patch designed to be removed at night. The patches are worn on the skin between the neck and the waist, and provide a steady delivery of nicotine through the skin. Patches come in varying strengths. After several weeks, users can move down to a patch that delivers a lower dose. Some people using the 24-hour patches experience sleep disturbances, and a few develop mild skin irritations, but generally side effects are few.
Two other nicotine delivery devices are available by prescription only. One is a nicotine nasal spray. It has the advantage of delivering nicotine rapidly, just as a cigarette does. Treatment with nasal spray usually lasts four
One prescription drug that is not nicotine replacement therapy has also been approved for treatment of nicotine dependence. Bupropion(Zyban) was originally developed as antidepressant medication that appears to increase dopamine levels in the brain. Bupropion has been shown to be effective in smoking cessation. It has the advantage of being a pill taken twice a day. Its side effects include dry mouth and insomnia; in addition, it may not be suitable for people with certain medical conditions.
Behavioral treatments are used to help smokers learn to recognize and avoid specific situations that trigger desire for a cigarette. They also help the smoker learn to substitute other activities for smoking. Behavioral treatments are almost always combined with smoker education, and usually involve forming a support network of other smokers who are trying to quit.
Behavioral treatments often take place in support groupseither in person or online. They are most effective when combined with nicotine reduction therapy. Other supportive techniques include the use of rewards for achieving certain goals and contracts to clarify and reinforce the goals. Aversive techniques include asking the smoker to inhale the tobacco smoke deeply and repeatedly to the point of nausea, so that smoking is no longer associated with pleasurable sensations. Overall, quit rates are highest (about 30%) when behavior modificationis combined with nicotine replacement therapy and tapering.
Many alternative therapies have been tried to help smokers withdraw from nicotine. Hypnosis has proved helpful in some cases, but has not been tested in controlled clinical trials. Acupuncture, relaxation techniques,
Smoking is a major health risk associated with nicotine dependence. About half of all smokers die of a smoking-related illness, often cancer. About 90% of lung cancers are linked to smoking. Smoking also causes such other lung problems as chronic bronchitis and emphysema, as well as worsening the symptoms of asthma. Other cancers associated with smoking include cancers of the mouth, esophagus, stomach, kidney, and bladder. Smoking accounts for 20% of cardiovascular deaths. It significantly increases the risk of heart disease, heart attack, stroke, and aneurysm. Women who smoke during pregnancy have more miscarriages, premature babies, and low-birth-weight babies. In addition, secondhand smoke endangers the health of nonsmokers in the smoker's family or workplace. Although most of these effects are not caused directly by nicotine, it is dependence on nicotine that keeps people smoking.
Even though it is difficult for smokers to break their chemical and psychological dependence on nicotine, they should remember that most of the negative health effects of smoking are reduced or reversed after quitting. Therefore, it is worth trying to quit smoking at any age, regardless of the length of time a person has had the habit.
The best way to avoid nicotine dependence and withdrawal is to avoid the use of tobacco products.
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Tish Davidson, A.M.