ABSTRACT
This chapter reviews the evidence supporting a genetic basis of drug addiction. The evidence from twin studies, genome-wide association studies and from animal studies is presented. All of these provide data to support the idea that at least some of the variability in drug misuse can be attributed to genetic differences. A brief summary of the self-administration procedure in animals is provided, and examples of data from laboratory animals that have been genetically modified or animals that have been selectively bred for different drug responses are provided. An example of the genetic basis for MDMA (“ecstasy”) misuse is presented and focuses on the available human and animal literature that has implicated polymorphisms in the genes that regulate pharmacokinetics and in the serotonin transporter gene. Limitations of these studies are briefly discussed and suggestions for further study using gene editing or other selective procedures to silence of to enhance the effect of drugs on various brain proteins are provided.
