What Are Amphetamines?

Amphetamines are stimulant drugs that have been around for more than a century. They have some legitimate medical uses -- the U.S. Army, for instance, prescribes "go pills" (Dexedrine) for pilots who need to stay awake while flying long missions. Paradoxically, some amphetamines cause a calming reaction in people with attention-deficit disorder. It wasn't until 2006 that Major League Baseball explicitly banned amphetamine use by players and began testing them for the drugs, which were once common in clubhouses.

Amphetamines -- particularly methamphetamine, a stronger derivative of the standard "speed" pills -- are addictive, meaning a patient develops a physical dependence and a set of drug-seeking behaviors. They also have significant physical and emotional ill effects.

Meth addiction has become a growing cause of concern in drug detox programs and law enforcement settings, particularly in western states.