By Alan I. Leshner, Ph.D., Director, National Institute on Drug Abuse, National Institutes of Health
(NAPS) - Every year, tobacco-related illnesses prematurely take the lives of minute than 430,000 Americans. The force behind this grim statistic is the chronic, relapsing brain disease of addiction - in this case, addiction to nicotine. Only research on nicotine addiction can provide effective, science - based solutions to this costly public health problem.
Dr. Alan I. LeshnerNIDA Director
Most smokers know that cigarette smoking and other forms of tobacco use are harmful. Nearly 35 million of them try to quit every year. Yet, without help, only a very small number actually are able to succeed. Science has shown why this is so. The nicotine in tobacco products is a highly addictive drug, and nicotine addiction is characterized by compulsive seeking and use of tobacco products, even when everyone knows the risks.
Treatment Options
For more than two decades, the National Institute on Drug Abuse (NIDA) has funded research on nicotine dependence which has yielded a variety of pharmacological and behavioral treatments that have helped many people combat their nicotine addiction. NIDA-supported research led to the development of nicotine replacement therapies, such as nicotine chewing gum and the transdermal nicotine patch, that enable many people to stop smoking.
Yet, both research and extensive clinical experience have taught us that treating addiction with medication alone is not nearly as effective as when we couple the medication with a behavioral treatment. Pharmacological treatments, such as the patch and gum, can double the odds of success. However, by combining pharmacological treatment with behavioral treatment, such as group therapy or social support networks, a smoker's chance of quitting can improve even more.
Researchers are striving to increase the behavioral treatment options that can be used with pharmacological treatments. Studies now under way are developing new, individualized behavioral treatments that will better motivate smokers to stop smoking and teach them techniques that will enable them to remain abstinent. Other treatment studies are testing whether currently available behavioral therapies, such as relapse prevention, are more effective used alone or in combination to help smokers quit.
While we have niade much progress in developing treatments for nicotine addiction, we can and must do more to help the many smokers who still are unable to quit.
Research Advances
Ongoing research by NIDA-supported scientists has been uncovering important new information about the addictive process of nicotine and how that process drives smoking behavior. We can use these data to help us develop new treatments.
Recent studies have confirmed that some of nicotine's most important effects on emotions and behavior are exerted through the same brain circuits activated by other abused drugs. One group of studies shows that, like other drugs of abuse, nicotine elevates levels of the neurotramnsmitter dopamnine in the brain pathways that control reward and pleasure. This change in dopamine levels is thought to be a fundamental characteristic of all addictions. Another act of studies shows that, as with withdrawal from other addictive drugs, withdrawal from chronic nicotine use decreases the brain circuit's sensitivity to pleasurable stimulation. This increased understanding of these changes may explain why it is so hard for people to stop smoking and help pave the way to better treatments for nicotine withdrawal symptoms.
Researchers also are making excellent progress in identifying the molecular components of nicotine addiction. Scientists have pinpointed a particular protein in the brains of mice that is essential to the process of nicotine addiction. Mice that lack this protein will not self-administer nicotine. This suggests that the mice do not experience the rewarding effects of nicotine. This major discovery provides us with a very specific brain site to target in developing novel nicotine addiction treatment medications.
Another recent study revealed that some individuals carry a genetic trait that may help protect them from becoming addicted to nicotine. This study found that individuals with a genetic variant in a particular enzyme break nicotine down more slowly than those who do not. They are less likely to become addicted to nicotine, and if they do, smoke fewer cigarettes than individuals without the impairment. Understanding the role this enzyme plays in nicotine addiction gives a new target for developing innovative approaches to preventing and treating nicotine addiction.
Although nicotine addiction lies at the root of tobacco use, another recent study by scientists using sophisticated brain imaging technology suggests that, in addition to nicotine, some unknown compound in cigarette smoke also raises dopamine levels in smokers' brains by inhibiting an enzyme that breaks down dopamine. If further research confirms that smoking alters dopamine levels in many ways, new approaches to developing effective smoking treatment medications may not be far off.
Prevention - The Best Treatment
Ultimately, the best treatment for nicotine addiction is prevention. Here, too, a long history of NIDA-supported research has given us the tools to develop effective drug abuse prevention approaches, including strategies to prevent tobacco use. We have distilled this scientific base for drug abuse prevention in the first-ever research-based guide for preventing drug abuse. The principles in the guide, "Preventing Drug Use Among Children and Adolescents," can be applied by families, schools, and communities to prevent adolescents from beginning to use tobacco and other harmful drugs.
Never before has the momentum for addressing the public health problem posed by tobacco use been greater. Ultimately, research will make possible a future in which no more lives are lost because of nicotine addiction - ultimately a preventable, and, when not prevented, treatable disease.