Cigarette smoking and tobacco use have met the surgeon general's primary criteria as well as additional criteria for drug dependence.
Drug dependence requires that the drug produce psychoactive effects.
Nicotine has been identified as the cause of tobacco dependence. First, nicotine provides positive reinforcement by stimulating nicotinic receptors to promote high self-administration rates. Second, nicotine causes a negative reinforcement in the form of withdrawal symptoms when nicotine is withheld after chronic use. Nicotine replacement therapy reduces the severity of withdrawal symptoms in smokers abstaining from tobacco. Nicotine replacement therapy allows the smoker to focus on psychosocial aspects of tobacco abstinence while receiving relief from withdrawal symptoms.