Substance abuse is a recognized medical brain disorder. It refers to the abuse of illegal or legal substances. Alcohol is the most common legal drug of abuse. Substance dependence describes abuse of drugs or alcohol that continues, even when serious problems related to their use have developed.

Genetics can play a part in whether you have problems with alcohol. But many other factors also have an influence.

Three kinds of prescription drugs are potentially addictive: opioids, tranquilizers, and stimulants.

Knowing about marijuana can help you recognize its use in children and others and help a user seek treatment.

Cocaine use ranges from once in a while to nonstop. There is no safe way to use the drug.

On the street, GHB is used for is ability to produce a feeling of euphoria and hallucinations.

LSD, also called acid, is one of the most commonly used hallucinogens or psychedelic drugs.

Until recently, heroin was not considered a problem among children of middle-class parents. But lately, it has been showing up in new places. Today the typical user could be a person from any race, part of the country, socio-economic level, or age.

Methamphetamine is related to the legal stimulant amphetamine, but has stronger effects.