Drug abuse may involve the overuse or misuse of prescribed or over-the-counter medications (particularly sleeping pills) or illicit drugs. Stimulants such as cocaine, “ecstasy,” “speed,” and other amphetamines, opioids (heroin, morphine and other sleep-inducing narcotics), and marijuana are currently the most widely abused illicit drugs. Currently, the most common form of substance abuse is alcohol abuse–the overuse of beer, wine, or liquor. The term “Substance Abuse” is the condition caused by regular excessive compulsive consumption of alcohol and/or physical addiction on a substance that results in a chronic disorder affecting the physical and mental health of a person. Substance abuse has a range of definitions related to disapproval overuse or overuse of mood-altering substances. These fall into four major categories: Drug or alcohol abuse may lead to addiction or substance dependence. Medically, dependence requires the development of tolerance leading to withdrawal symptoms.