Smoking is highly addictive, and although the number of smokers has halved in the last 40 years in the United States, smoking is still responsible for hundreds of thousands of preventable deaths annually. Understanding what makes smoking so addictive is important, as it can result in better strategies for smoking cessation. Dopamine is a chemical produced in the brain which has been associated with pleasure and reward, and as it is released when smoking tobacco, it is thought that this part of the reason for the addictive nature of smoking.
Dopamine as a Neurotransmitter
Dopamine is a neurotransmitter in the brain which acts on dopamine receptors to cause a response in neurons. The response is dependent on the location of the receptors in the brain. For example, dopamine is important in the movement and coordination centers of the brain. Research has also shown that dopamine is released in large quantities in the limbic system, the part of the brain responsible for motivation and reward, says the National Institute on Drug Abuse.
Dopamine and Reward
Dopamine has therefore been called your reward system, and it has been shown that activities such as eating and sex, which give you pleasure or a feeling of well-being, are correlated with a release of dopamine. Drugs such as cocaine and amphetamines have also been shown to result in increased dopamine secretion, and it is widely recognized that this is at least partly responsible for the heightened pleasure experienced by drug-takers, according to research at the State University of New York-Buffalo.
Dopamine and Smoking
Tobacco smoke contains over 4,000 chemicals and one of these is nicotine, a highly addictive substance, which has been shown to be more addictive than heroin, according to the University of Minnesota. This chemical enters the blood and after about seven seconds, it enters the brain, affecting exactly the same dopamine receptors, giving the brain the message that a rewarding activity has just been performed. Smokers report a feeling of calmness and mild euphoria when they have a puff of a cigarette.
Dopamine and Addiction
If your smoking habit is prolonged, your brain becomes accustomed to this reward. According to the American Heart Association, nicotine has a half-life of only two hours, so the effects wear off quickly; this means that your brain asks for this reward when you haven't had a cigarette for a while, an experience known as a craving. Prolonged smoking will therefore result in an addiction, and rather than enhancing the feeling of well-being, the smoker will need a cigarette just to feel normal.
Dopamine and Smoking Cessation
Quitting smoking is notoriously difficult precisely because of the addictive nature of nicotine, which, apart from dopamine, affects other neurotransmitter systems in the brain. Only 25 percent of people successfully quit smoking without relapsing for at least one year, says the Tobacco Facts website. One of the few medications that has been shown to be effective in increasing the success rate is Bupropion, a chemical that slightly increases the levels of dopamine in the brain. By doing this, researchers argue, the brain no longer needs the dopamine high caused by smoking, and smokers experience fewer cravings, according to the Tobacco-Related Disease Research Program. If you are trying to quit, consult your physician for advice.