Tobacco is one of the most widely abused substances in the world. It is highly addictive. Although tobacco use appears to be on the decline in the United States, the Centers for Disease Control and Prevention (CDC) estimates that nearly 20 percent of adults still smoke. This is despite nearly 70 percent of smokers wanting to quit.

Nicotine, the main addictive chemical in tobacco, causes a rush of adrenaline when absorbed in the bloodstream or inhaled via cigarette smoke. Nicotine also triggers an increase in dopamine—the brain’s “happy” chemical. This stimulates the area of the brain associated with pleasure and reward. Like any other drug, use of tobacco over time can cause a physical and psychological addiction. This is also true for smokeless forms of tobacco such as snuff and chewing tobacco.