Alternate Names : Addiction - Drug, Drug Addiction

Definition

Drug dependence (addiction) is compulsive use of a substance despite negative consequences which can be severe; drug abuse is simply excessive use of a drug or use of a drug for purposes for which it was not medically intended.

Physical dependence on a substance (needing a drug to function) is not necessary or sufficient to define addiction. There are some substances that don't cause addiction but do cause physical dependence (for example, some blood pressure medications) and substances that cause addiction but not classic physical dependence (cocaine withdrawal, for example, doesn't have symptoms like vomiting and chills; it is mainly characterized by depression).

See also drug abuse and drug abuse first aid.