Speed is a key reason that tobacco is as likely to hook you as is heroin, because the risk of addiction is as much about the method of delivery as it is the substance being imbibed. Draw on a cigarette, and the smoke will carry the nicotine from your mouth to the blood in your lungs to your brain in ten seconds. That’s ten seconds from feeling the desire to smoke—thanks to dopamine—to feeling the full reward of that puff on the cigarette, thanks to your homemade opioids.
