ALCOHOL ADDICTION AND ABUSE: AN EVOLUTIONARY PERSPECTIVE

Background and Aim : The Psychedelics which can produce abuse or dependence are numerous in nature but availability of them in large quantities has relatively short history comparing emergence of Homo-sapiens. This indicates an evolutionary mismatch.Methods : Reviewing literature about alcohol addiction and abuse from evolutionary Viewpoint.Results : In Cro-Magnon humans, the activity of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) is different between ethnic groups which indicates adaptive variations to different diets in various geographic areas during the last 100,000 years. For example some people in eastern Asia have an isoenzyme which metabolizes acetaldehyde slower than isoenzyme found in Caucasians. Slower metabolization of alcohol leads to acetaldehyde concentration which in turn give rise to an aversive reaction including nausea and malaise.Conclusion : Availability of large quantities of alcohol has produced the problems of alcohol addiction and abuse in new environmental condition. This is clearly an example of mismatch of evolutionary traits in man in new environmental conditions. The Psychedelic effects of areca, erythroxilum coca and alcohol could enhance group cohesion in rituals and feasts. Besides, these substances were used as analgesics. However flooding of brain with substances which have various effects on brain metabolism is not adaptive because this rate is beyond detoxification capacity of organism. These substances exert their effects on brain metabolism by seizing evolved systems of brain which are responsible for adaptive signalling of social reward and attachment.

کلیدواژه ها:

alcohol addiction ، alcohol abuse ، evolutionary Perspective.