RT Book, Section A1 Hilal-Dandan, Randa A1 Brunton, Laurence L. SR Print(0) ID 1127549831 T1 Drug Addiction T2 Goodman and Gilman's Manual of Pharmacology and Therapeutics, 2e YR 2016 FD 2016 PB McGraw-Hill Education PP New York, NY SN 9780071769174 LK hemonc.mhmedical.com/content.aspx?aid=1127549831 RD 2024/03/29 AB The terminology used in discussing drug dependence, abuse, and addiction has long been confusing. Confusion stems from the fact that repeated use of certain prescribed medications can produce neuroplastic changes resulting in 2 distinctly abnormal states. The first is dependence, or "physical" dependence, produced when there is progressive pharmacological adaptation to the drug resulting in tolerance. In the tolerant state, repeating the same dose of drug produces a smaller effect. If the drug is abruptly stopped, a withdrawal syndrome ensues in which the adaptive responses are now unopposed by the drug. The appearance of withdrawal symptoms is the cardinal sign of "physical" dependence. Addiction, the second abnormal state produced by repeated drug use, occurs in only a minority of those who initiate drug use; addiction leads progressively to compulsive, out-of-control drug use.