Smoking addiction is a powerful physical and psychological dependence on nicotine, the psychoactive drug found in tobacco. Unlike many other addictions, smoking is often woven deeply into daily life—coffee breaks, driving, or socializing—making it uniquely difficult to quit. When inhaled, nicotine reaches the brain within 10 seconds, triggering a rapid release of dopamine that creates a fleeting sense of pleasure or relaxation. However, this effect fades quickly.