The Science of Nicotine Dependence

Nicotine delivered by cigarettes creates dependence

Nicotine reaches the brain within 11 seconds, binding to nicotinic receptors and momentarily satisfying the urge to smoke.1,2 
Long-term effects of smoking include an increased number of nicotinic receptors, leading to an increased need for nicotine.3,4

Nicotine delivered by cigarettes creates dependence
Smoking increases the number of nicotinic receptors in the brain

Nicotine from smoking cigarettes increases the number of receptor sites in the brain3,4 

Nicotine can activate neurotransmitters or chemicals in the body that can influence behavior and mood.1,3

Smoking cessation decreases the number of nicotinic receptors in the brain

Smoking cessation helps reduce the number of nicotinic receptors in the brain3

In one post-mortem study, 9 smokers who had quit for at least 2 months had similar nicotinic receptor levels as nonsmokers.3

E-cigarettes are unproven and nontherapeutic

E-cigarettes are unproven and nontherapeutic

  • A World Health Organization study group concluded there was insufficient evidence to demonstrate that e-cigarettes are an effective smoking-cessation aid or that they deliver sufficient nicotine to be used as a smoking-cessation tool5
  • The US Food and Drug Administration issued a press release discouraging the use of e-cigarettes and stated concerns that these products may be marketed to young people and lack appropriate health warnings6


1. Benowitz NL. Clinical pharmacology of nicotine: implications for understanding, preventing, and treating tobacco addiction. Clin Pharmacol Ther. 2008;83(4):531-541. 2. Benowitz NL. Cigarette smoking and nicotine addiction. Med Clin North Am. 1992;76(2):415-437. 3. Breese CR, Marks MJ, Logel J, et al. Effect of smoking history on [3H]nicotine binding in human postmortem brain. J Pharmacol Exp Ther. 1997;282(1):7-13. 4. Perry DC, Dávila-García MI, Stockmeir CA, Kellar KJ. Increased nicotinic receptors in brains from smokers: membrane binding and autoradiography studies. J Pharmacol Exp Ther. 1999;289(3):1545-1552. 5. World Health Organisation. Backgrounder on WHO report on regulation of e-cigarettes and similar products. August 20, 2015. 6. US Food and Drug Administration. FDA warns of health risks posed by e-cigarettes. Published July 22, 2009. Accessed August 20, 2015