Amphetamine contracted from alpha‑methylphenethylamine) is a potent central nervous system (CNS) stimulant of the phenethylamine class that is used in the treatment of attention deficit hyperactivity disorder (ADHD) and narcolepsy. Amphetamine was discovered in 1887. Much larger doses of amphetamine are likely to impair cognitive function and induce rapid muscle breakdown. Substance dependence (i.e., addiction) is a serious risk of amphetamine abuse, but only rarely arises from medical use. Very high doses can result in psychosis.