Technically, nicotine is not significantly addictive, as nicotine administered alone does not produce significant reinforcing properties. However, only after coadministration with an MAOI, such as those found in tobacco, nicotine produces significant behavioral sensitization, a measure of addiction potential. This is similar in effect to amphetamine.
Modern research shows that nicotine acts on the brain to [...]

 
Scientifically nicotine is described as an alkaloid found in the nightshade family of plants (Solanaceae) which constitutes approximately 0.6–3.0% of dry weight of tobacco, with biosynthesis taking place in the roots, and accumulating in the leaves. Due to its properties it was used in the past as antiherbivore chemical and insecticide. Even today nicotine analogs [...]