Nicotine is a stronger addiction than most people realize–and cigarettes are a very efficient nicotine delivery system. Each puff sends nicotine to the brain within 10 seconds, activating areas of the brain that produce feelings of pleasure and reward by raising dopamine levels. Dopamine is the same substance involved in addiction like cocaine and heroin. So we have another puff. And another. Soon the brain’s chemical structure actually changes. It becomes hooked into wanting more and more nicotine to make the effects last. When the brain stops getting the nicotine it’s used to, we begin to feel withdrawal cravings–actually the brain craving nicotine. As this nicotine addiction sets in, the brain links everyday habits with smoking, boosting the role of cigarettes. Normal everyday activities begin to trigger the urge to smoke. Drinking coffee in the morning. Talking on the phone. Work breaks. Driving. So when you try to quit smoking, you’re actually fighting a battle on two fronts: 1) physical–that is, nicotine addiction–and 2) habitual, the activities, moods and events linked with smoking.