Tobacco contains the alkaloid, nicotine. Dried tobacco leaves are mainly smoked in cigarettes, cigars, pipe tobacco, and flavored shisha tobacco. They are also consumed as snuff, chewing tobacco, and dipping tobacco. Nicotine is one of the most heavily used addictive drugs and the leading preventable cause of disease, disability, and death. When we smoke, nicotine reaches the brain within 10 seconds of inhalation and increases the level of the neurotransmitter called dopamine which affects memory, sleep, mood, pleasurable reward, behavior and cognition.
.