What is nicotine?

Nicotine is the psychoactive drug in tobacco products that produces dependence.1  Most smokers are dependent on nicotine.1

Tobacco use is associated with psychological and physiological dependence.2  Frequently reported symptoms of psychological dependence include feeling dependent on cigarettes, using more cigarettes than intended, and continuing to smoke cigarettes despite experience problems.2  Frequently reported symptoms of physiological dependence include symptoms of tolerance and withdrawal.2

Nicotine and addiction

Nicotine addiction has been classified as a substance abuse disorder by the World Health Organization International Classification of Diseases (ICD – 10), which lists the disorder as “tobacco dependence”.1  Research suggests nicotine may be as addictive as heroin, cocaine, and alcohol.2  Addiction is characterized by “compulsive drug seeking and abuse”, even with knowledge of negative health consequences.3  Almost 35 million smokers attempt to quit smoking a year, but over 85 percent of those who quit without support relapse.3

Research shows that nicotine activates reward pathways in the brain.  Nicotine increases levels of the chemical dopamine in the brain reward pathways, which increases feelings of pleasure.2  As a result, the long-term use of nicotine results in addiction.2

The delivery of nicotine to the brain also enhances nicotine’s addictive properties.3  By inhaling tobacco smoke, the average smoker takes in 1-2 milligrams of nicotine per cigarette.3  Cigarette smoking rapidly distributes nicotine to the brain and drug levels peak within 10 seconds of inhalation.3  However, the reward properties of nicotine dissipate quickly, which causes the smoker to continue to smoke to maintain the pleasurable feelings.3  The average smoker will take 10 puffs of a cigarette over a period of 5 minutes while the cigarette is lit.3  Consequently, if a person smokes 1 ½ packs a day, he or she will take in 300 “hits” of nicotine to the brain daily.3

Nicotine can also be delivered to smokers through cigars, pipes, and smokeless tobacco.  In the case of cigars, pipes, and smokeless tobacco, nicotine is absorbed through the mucosal membranes and reaches peak blood level and the brain more slowly.3

Nicotine dependence and psychiatric comorbidity

Research has shown a strong association between nicotine dependence and psychiatric comorbidity.2  Approximately 44 percent of all cigarettes consumed in the United States are consumed by people with mental health issues of substance abuse disorders.2  Studies have also shown the more severe the nicotine dependence, the more likely was the association with comorbid disorders.2

Nicotine and withdrawal

Nicotine produces withdrawal symptoms in smokers.2  Withdrawal symptoms include irritability, nicotine cravings, depression, anxiety, attention deficits, sleep problems, and increased appetite.2  Withdrawal symptoms are related to the pharmacological effects of nicotine, but behavioral triggers may worsen withdrawal symptoms.3  For example, the smell, feel, or even sight of a cigarette may be associated with pleasurable feelings and may worsen the cravings for a cigarette.3

Nicotine and Adolescents

Nicotine is particularly problematic for adolescents because it can change the way the brain forms and can have lasting consequences.4 With the increase of e-cigarette use by adolescents, it is important for both parents and providers to not only know what to say in their conversations but how to say it as well. Addressing the misconceptions surrounding nicotine use and educating youth about the facts is a vital combination. For more information about the effects of nicotine on adolescents and for tips on how to address the dangers of nicotine use with adolescents, please view our brochure on Nicotine and Adolescents.

  1. Fiore MC, Jaén CR, Baker TB, Bailey WC, Benowitz NL, Curry SJ, Dorfman SF, Froelicher ES, Goldstein MG, Froelicher ES, Healton CG, et al. Treating tobacco use and dependence: 2008 update—Clinical practice guidelines. Retrieved October 9, 2012 from
  2. U.S. Department of Health and Human Services. How tobacco smoke causes disease: The biology and behavioral basis for smoking-attributable disease: A report of the Surgeon General. Atlanta: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health, 2010 Retrieved October 9, 2012 from
  3. National Institute on Drug Abuse. (2012). Research reports: Tobacco addiction. Retrieved October 23, 2012 from
  4. Yuan, M., Cross, S. J., Loughlin, S. E., & Leslie, F. M. (2015). Nicotine and the adolescent brain. The Journal of physiology593(16), 3397–3412. doi:10.1113/JP270492