It was embraced by '60s motorcycle gangs, who marketed it as speed. But the home-cooked meth, sometimes rife with impurities, is consumed in prodigious amounts by the addicts, and casual use can quickly transform to addiction. They forgo sleep and food, and often become skittish, irritable or paranoid. Their teeth rot. And they often lose tremendous amounts of weight.
Studies indicate that meth use also does less-visible damage.
According to the National Institute on Drug Abuse, meth attacks the nerve endings of brain cells containing dopamine, a chemical messenger that plays a role in movement and pleasure.