[Extension of the concept of withdrawal signs]

If the conditions including normal-dose dependence in which withdrawal signs are observed in the absence of definite psychic dependence are classified as dependence, this classification should be regarded as inappropriate extension of the concept of drug dependence. These conditions should be diagnosed as 'withdrawal' as specified by the DSM-5 or ICD-10. Advancements of research have clarified that an increased number of drugs cause withdrawal signs. Some Japanese researchers use the concept of 'withdrawal signs of psychic dependence.' Their definition of drug dependence and concept of withdrawal signs, however, are different from the definition established by the WHO and the researchers specializing in this field. Thus, the concept of 'withdrawal signs of psychic dependence' raises a lot of questions.