[Mechanism of drug dependency: answers to the questions of KATO].
The complicated mechanisms of drug dependency were discussed from the perspective of a reward, especially the perspective of psychic dependency of the brain. In Kato's article, the following questions were raised. (1) Improper usage of terminology in describing the objective pharmacological behavior and describing the subjective psychic experience, e.g. the term "obsessional comfort". (2) The enhanced effects of morphine and d-amphetamine in ICSS (intracranial self-stimulation) were not suitably regarded, as these might be the results of stimulus current running in the brain. The conclusion that "morphine and d-amphetamine are 2 kinds of addictive drugs due to the reinforcement effects on ICSS" appears to be putting the incidental before the fundamental because these are addictive drugs in clinical use. (3) It was unknown why the basic problem of drug dependency was limited to psychic stimulant (antihypnotic, etc.), and why only opiates were represented as an addictive drug. (4) The conclusion that the reinforcement effects of barbital and benzodiazepine were not observed in ICSS contradicted Kato's conclusion, in which the reinforcement effects were detected in an experiment involving self-administration. (5) He reiterated that the usage of terminology was confused in describing the psychic experience and pharmacological behavioral. In response to the comments of the editors, I would answer the questions as follows: It is well-known that the terminologies used in psychiatry are strict and prudent. This should also be the case in the description of pharmacological behaviors in animal models. The author admitted Kato's profound relevant experiences in drug dependency, and did not disapprove of his criticisms about the terminology used in the article to describe objective behaviors and observe subjective experience. That article was excerpted from one of my lectures, which to some extent allowed freedom in phrases and sentences. The following are my answers to Kato's questions.
Takigawa
M
M
Dept. of Neuropsychiatry, Faculty of Medicine, Kagoshima University.
D000818:Animals; D001921:Brain / Q000502:physiology; D006801:Humans; D009480:Neuropharmacology; D011570:Psychiatry; D012054:Reinforcement, Psychology; D012201:Reward; D012653:Self Stimulation; D019966:Substance-Related Disorders; D009626:Terminology as Topic