What is the addictive drug found in all forms of tobacco?

Nicotine is the addictive substance present in all forms of tobacco. It acts on the brain's reward system, leading to feelings of pleasure and relaxation, which reinforces the behavior of tobacco use. This addiction can develop rapidly, making it difficult for users to quit once they start.

Caffeine is a stimulant found primarily in coffee and tea, but it does not have the same addictive properties associated with tobacco. Cotinine is a metabolite of nicotine, meaning it is produced when nicotine is broken down in the body, and is often used as a biomarker to measure exposure to tobacco. Tar refers to a sticky substance produced by burning tobacco that contains various harmful chemicals, but it is not the addictive component itself. Thus, while these substances are associated with tobacco use, none possess the addictive qualities of nicotine, confirming that it is indeed the correct choice.