30 December 2016

Considerable recent research suggests yet another, quite orthogonal mechanism for tolerance. The concept is simple: When an animal has become accustomed to receiving a drug in a certain situation and is again presented with that same situation, it anticipates the drug administration and makes compensatory responses that serve to reduce the impact of the impending presence of the drug. Given this mobilization of the body's homeostatic processes before the actual drug presentation, the drug is effectively compromised, and the result is less total drug effect or increased drug tolerance.

Redish, A. D., Steve Jensen, and Adam Johnson. 2008. A unified framework for addiction: vulnerabilities in the decision process. The article gives a summary of some theoretical approaches explaining the essence of the addiction. The authors describe seven major types of such theories.
(1) Оpponent processes. This approach is, first of all, related to the studies of the National Institute on Drug Abuse under the supervision of Nora Volkow and George Koob. It’s main point is that the impact of alcohol and other drugs on the reward center changes its functioning, which results the replacing homeostasis, the natural harmony of neurobiological processes in the body with allostasis, the adaptation of neurotransmitter system to drug administration followed by the regulation of the process by this system. In particular, these mechanisms are used to explain the withdrawal syndrome that happens after an abrupt withdrawal from alcohol consumption