Drug abuse

Drug abuse, non-medical use of certain chemical substances that can induce unusual states of consciousness, relieve pain, increase endurance, or heighten sensation. The use of such substances very likely predates the historical record, and cultures and civilizations have taken varying attitudes to prohibition or legalization of various substances. In modern times, drug abuse refers to dependence upon any of a range of narcotics (marijuana, hashish, morphine, opium, and their derivatives), stimulants (cocaine and amphetamines), depressants (alcohol, barbituates, and sedatives), and many hallucinogenic agents.

See also: Drug.