All tobacco products contain substantial amounts of nicotine, which is absorbed readily from tobacco smoke in the lungs and from smokeless tobacco in the mouth or nose. Experts in the field of substance abuse consider tobacco dependence to be as strong or stronger than dependence on such substances as heroin or cocaine. Smoking typically begins in adolescence. If a person remains smoke-free throughout adolescence, it is highly unlikely that he or she will ever begin smoking. Therefore, it is vital that intensive efforts be made to help young people stay smoke-free.
Nicotine dependence is clearly a major barrier to successful cessation.