As a general term, the state of needing or depending on something or someone for support or to function or survive. As applied to alcohol, nicotine and other drugs, the term implies the need for repeated doses to feel good or to avoid feeling bad. The term is often used interchangeably with addiction and alcoholism. The term refers to both physical and psychological elements. Psychological or psychic dependence refers to the experience of impaired control over drinking or drug use, while physiological or physical dependence refers to tolerance and withdrawal symptoms.

(Adapted from Lexicon of Alcohol and Drug Terms, World Health Organization, 1994).