[The definition of drug dependence]

A number of definitions of drug dependence exist. The current idea is summarized as follows: drug dependence is a chronic, progressive disease characterized by significant impairment that is directly associated with persistent and excessive use of a psychoactive substance. Impairment may involve physiological, psychological, or social dysfunction. The most helpful one to physicians is based on the descriptions of WHO's ICD and APA's DSM. The criteria for drug dependence of ICD-10 and DSM-IV are given in this paper. To facilitate the harmonization process of the forthcoming development of DSM V and ICD-11, differences in the both definitions are also discussed.