Methamphetamine is an addictive stimulant drug that strongly activates certain systems in the brain. Methamphetamine is closely related chemically to amphetamine, but the central nervous system effects of methamphetamine are greater. Both drugs have some medical uses, primarily in the treatment of obesity, but their therapeutic use is limited.
Methamphetamine is made in illegal laboratories and has a high potential for abuse and dependence. Street methamphetamine is referred to by many names, such as "speed," "meth," and "chalk." Methamphetamine hydrochloride, clear chunky crystals resembling ice, which can be inhaled by smoking, is referred to as "ice," "crystal," and "glass."
In 1997, 4.4 percent of US high school seniors had used crystal methamphetamine at least once in their lifetimes – an increase from 2.7 percent in 1990. The data show that 2.3 percent of seniors reported past year use of crystal methamphetamine in 1997 – an increase from 1.3 percent in 1990.
According to the 1996 US National Household Survey on Drug Abuse (NHSDA), 4.9 million people (aged 12 and older) had tried methamphetamine at least once in their lifetimes (2.3 percent of population). This is not a statistically significant increase from 4.7 million people (2.2 percent) who reported using methamphetamine at least once in their lifetime in the 1995 NHSDA.