Nicotine

What causes nicotine addiction?

Nicotine is an addictive drug. It causes changes in the brain that make people want to use it more and more. In addition, addictive drugs cause unpleasant withdrawal symptoms. The good feelings that result when an addictive drug is present — and the bad feelings when it’s absent — make breaking any addiction very difficult. Nicotine addiction has historically been one of the hardest addictions to break.

Brain Defenses Create Dependency

A toxic poison, the brain’s defenses fought back but in doing so they had no choice but to also turn down the mind’s sensitivity to acetylcholine, the body’s conductor of an entire orchestra of neurochemicals.

Reseach suggest that aside from desensitizing receptors, that in some regions the brain diminished the number of receptors available to receive nicotine, in others it diminished available transporters but in most affected regions it grew or activated millions and millions of extra acetylcholine receptors (a process known as “up-regulation“), almost as if trying to protect itself by more widely disbursing the arriving pesticide.

There was only one problem. All the physical changes engineered a new tailored neuro-chemical sense of normal built entirely upon the presence of nicotine. Now, any attempt to stop using it would come with a risk of intermittent temporary hurtful anxieties and powerful mood shifts. A true chemical addiction was born. Returning home to the “real you” now had a price. Gradually the calmness and comfort associated with being the “real you,” of going weeks and months without once wanting for nicotine, faded into distant or even forgotten memory.

The brain’s protective adjustments insured that any attempt to stop would leave you temporarily desensitized. Your dopamine reward system would briefly offer-up few rewards, the mind’s fight or flight pathways might see nicotine’s absence as danger and sound emotional anxiety alarms throughout the body, and mood circuitry might briefly leave you feeling depressed.

The 1988 Surgeon General’s Report, “Nicotine Addiction,” concluded that:

• Cigarettes and other forms of tobacco are addicting.
• Nicotine is the drug that causes addiction.
• Pharmacologic and behavioral characteristics that determine tobacco addiction are similar to those that determine addiction to drugs such as heroin and cocaine.

What else does nicotine do to the body? When a person smokes a cigarette, the body responds immediately to the chemical nicotine in the smoke. Nicotine causes a short-term increase in blood pressure, heart rate and the flow of blood from the heart. It also causes the arteries to narrow. The smoke includes carbon monoxide, which reduces the amount of oxygen the blood can carry. This, combined with the nicotine effects, creates an imbalance between the demand for oxygen by the cells and the amount of oxygen the blood can supply.

How does nicotine in cigarettes increase the risk of heart attack? Cigarette smoking may increase the risk of developing hardening of the arteries and heart attacks in several ways. First, carbon monoxide may damage the inner walls of the arteries, encouraging fatty buildups in them. Over time, this causes the vessels to narrow and harden. Nicotine may also contribute to this process. Smoking also causes several changes in the blood that make clots — and heart attack — more likely.

What are the symptoms of nicotine withdrawal?

• irritability
• impatience
• hostility
• anxiety
• depressed mood
• difficulty concentrating
• restlessness
• decreased heart rate
• increased appetite or weight gain

How long does nicotine stay in the body? From 85–90 percent of nicotine in the blood is metabolized by the liver and excreted from the kidney rapidly. The estimated half-life for nicotine in the blood is two hours. However, smoking represents a multiple dosing situation with considerable accumulation during smoking. Therefore, it can be expected that blood nicotine would persist at significant levels for six to eight hours after smoking stopped.

A toxic poison, the brain’s defenses fought back but in doing so they had no choice but to also turn down the mind’s sensitivity to acetylcholine, the body’s conductor of an entire orchestra of neurochemicals.

Reseach suggest that aside from desensitizing receptors, that in some regions the brain diminished the number of receptors available to receive nicotine, in others it diminished available transporters but in most affected regions it grew or activated millions and millions of extra acetylcholine receptors (a process known as “up-regulation“), almost as if trying to protect itself by more widely disbursing the arriving pesticide.

There was only one problem. All the physical changes engineered a new tailored neuro-chemical sense of normal built entirely upon the presence of nicotine. Now, any attempt to stop using it would come with a risk of intermittent temporary hurtful anxieties and powerful mood shifts. A true chemical addiction was born. Returning home to the “real you” now had a price. Gradually the calmness and comfort associated with being the “real you,” of going weeks and months without once wanting for nicotine, faded into distant or even forgotten memory.

The brain’s protective adjustments insured that any attempt to stop would leave you temporarily desensitized. Your dopamine reward system would briefly offer-up few rewards, the mind’s fight or flight pathways might see nicotine’s absence as danger and sound emotional anxiety alarms throughout the body, and mood circuitry might briefly leave you feeling depressed.

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.

What Are the Extent and Impact of Tobacco Use?

According to the 2007 National Survey on Drug Use and Health, an estimated 70.9 million Americans aged 12 or older reported current use of tobacco—60.1 million (24.2 percent of the population) were current cigarette smokers, 13.3 million (5.4 percent) smoked cigars, 8.1 million (3.2 percent) used smokeless tobacco, and 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.

NIDA’s 2008 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 7 percent of 8th-graders, 12 percent of 10th-graders, and 20 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 post-traumatic stress disorder, bipolar disorder, major depression, and other mental illness is two- 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. health care 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 health care 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 4,000 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, there has also been a recent increase in the use of 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 mg 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 1½ packs (30 cigarettes) daily gets 300 “hits” of nicotine to the brain each day. In those who typically 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.

Reference Sources: NIDA (National Institute on Drug Abuse), American Heart Association, and WhyQuit.com

• Alcohol addiction
• Marijuana addiction
• Cocaine addiction
• Amphetamine addiction
• Opiate/Opioid addiction (includes heroin and prescription pain medicine)
• Tranquilizers and benzodiazepines