Genes and Genetic Testing in Addiction Medicine

This article will detail the gene addiction connection: gene alleles and genetic testing. The Neurogeneticist Kenneth Blum, with Ernest Noble, published the first study to associate the Dopamine D2 Receptor Gene (DRD2) A1 allele and severe alcoholism in JAMA. This research confirmed an association preceded by a theoretical construct that identified the neurotransmitter interaction leading to dopamine release in the mesolimbic system as the “Brain Reward Cascade” in 1989. Earlier basic research had identified the role endorphins played in alcoholism and the blocking effect of Naloxone, an opioid-receptor antagonist in alcohol dependence. It supported the concept of a common mechanism between alcohol and opiates. Blum et al. also developed a theory based on binding studies and other basic research that identified a “hypodopaminergic” trait/state caused by either genetics, stress, or toxicity as “Reward Deficiency Syndrome” (RDS). Blum's group developed a nutraceutical therapy (scientific code) KB220 to treat RDS and the Addiction Risk Severity (GARS) test to identify genetic risk for RDS. Reward deficiency syndrome, characterized as a relative failure of the neurotransmitter system in brain reward mechanisms, has been linked to dopaminergic dysfunction, acute excess, or chronic deficit of dopamine release in the brain reward circuitry. The reward deficiency behaviors include drug and non-drug addictive, compulsive, and impulsive behaviors.