[Pharmacogenetic studies on drug dependence].

Great strides have been made in recent years in researchers' knowledge and understanding of genetic factors contributing to drug dependence. In this paper, pharmacogenetic studies on drug dependence are reviewed. The strain which has been maintained by inbreeding for 20 or more generations may be regarded as being genetically uniform. Significant differences between inbred strains on a particular response represent presumptive evidence of genetic determination of that response. Selective breeding is another genetic approach and refers to the systematic intermating of selected individuals for the purpose of changing the genetic and phenotypic characteristics of a population. This usually takes the form of changing the population mean in two opposite directions, such as AA and ANA, LS and SS, etc. Using inbred animal strains and selective lines, a variety of evidence indicates that acute effects of, tolerance to, and dependence on abusable drugs are controlled by genetic factors. Many investigations have compared the effects of abusable drugs with various biochemical traits. The use of certain genetically defined animal models can be very helpful in studies of drugs of abuse. The choice of model will be influenced by the aims of the study.