Genética da dependência à cocaína Genetics of cocaine dependence

Many factors have been involved in the susceptibility to cocaine dependence that is a mental disorder characterized for a complex interaction between genetic and environmental components, which include differences related to the target of action of the substance, psychological processes that drive the patient to the drug use, etc. The fact that there is no regular pattern for genetic transmission, the Mendelian inheritance is not related to the genetics of cocaine dependence. The pattern of inheritance of addiction is complex, involving the participation of many genes that interact with themselves. The contribution of the environmental factors are also important, conducting the patient to a first contact with the drug, and after that to a regular use and a future abuse. This mechanism characterizes the disorder with a complex inheritance (polygenic transmission with a environmental interaction). The used strategies to the investigation of the genetic compound of the disorders that present a complex pattern of inheritance may be classified in geneticepidemiological and genetic-molecular studies. Thus, the present report aims to present and discuss the methods and results obtained by the genetic studies of cocaine dependence.