Drug abuse has a wide range of definitions, all of them relating to the use, misuse or overuse of a psychoactive drug or performance enhancing drug for a non-therapeutic or non-medical effect. Some of the most commonly abused drugs include alcohol, amphetamines, barbiturates, caffeine, cannabis, cocaine, methaqualone, nicotine, opium alkaloids, and minor tranquilizers. Use of these drugs may lead to criminal penalty in addition to physical, social, and psychological harm.[1] Other definitions of drug abuse fall into four main categories: Public health definitions, Mass communication and vernacular usage, Medical definitions, and Political and criminal justice definitions.