drug abuse, the use of a drug for a nontherapeutic effect. Some of the most commonly abused drugs are alcohol; nicotine; marijuana; amphetamines; barbiturates; cocaine; methaqualone; opium alkaloids; synthetic opioids; benzodiazepines, including flunitrazepam (Rohypnol); gamma-hydroxybutyrate; 3,4 methylenedioxymethamphetamine (MDMA, ecstasy); phencyclidine; ketamine; and anabolic steroids. Drug abuse may lead to organ damage, addiction, and disturbed patterns of behavior. Some illicit drugs, such as heroin, lysergic acid diethylamide, and phencyclidine hydrochloride, have no recognized therapeutic effect in humans. Use of these drugs often incurs criminal penalty in addition to the potential for physical, social, and psychological harm. See also drug addiction.
