The chemical in cigarette smoke to which people often become addicted is called .

The chemical in cigarette smoke to which people often become addicted is called nicotine. Nicotine is a stimulant drug that affects the nervous system, leading to the release of neurotransmitters such as dopamine, which play a significant role in the pleasure and reward pathways of the brain. This release creates sensations of pleasure and relaxation, making smoking a reinforcing behavior that can lead to dependency. The rapid absorption of nicotine through the lungs contributes to its addictive nature, as it reaches the brain within seconds. Over time, the body becomes accustomed to nicotine, and the absence of it can lead to withdrawal symptoms, reinforcing the cycle of addiction.