Drug dependence means that a person needs a drug to function normally. Abruptly stopping the drug leads to withdrawal symptoms. Drug addiction is the compulsive use of a substance, despite its negative or dangerous effects.
A person may have a physical dependence on a substance without having an addiction. For example, certain blood pressure medications do not cause addiction but they can cause physical dependence. Other drugs, such as cocaine, cause addiction without leading to physical dependence.
Tolerance to a drug (needing a higher dose to attain the same effect) is usually part of addiction.
Drug abuse Drug abuse first aid
Drug addiction; Addiction - drug; Dependence on drugs
Review Date: 02/11/2010
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.