Genes can provide information about drug addiction, treatment

December 7, 2018

Understanding the genes that play a role in addiction could help predict who becomes addicted and how people might respond to treatment, said Dr. Jeremy Day, assistant professor of Neurobiology at the University of Alabama at Birmingham. Day provided the College’s Alice Mclean Stewart Endowed Lecture for Addiction Education on November 30. His talk was titled “Control-Alter-Delete: Gene Regulatory Mechanisms in Drug Abuse and Addiction.” “If there’s a mutation in the dopamine receptor, for example, it could make an individual vulnerable to addiction,” Day said. “The challenge is understanding what genes are important in addiction.” The National Institute on Drug Abuse reports there were 72,000 drug overdose deaths last year, exceeding the number of deaths from car accidents. In 2016, half of all high school seniors nationwide reported using illicit drugs, according to the NIDA. Day characterized drug addiction as a chronic, relapsing disorder. But, he said, not everyone who uses drugs becomes addicted – only about 20 percent do. Most illicit drugs work by elevating dopamine levels, an important chemical messenger in the brain involved with reward, motivation, memory, attention and even regulating body movements. When released in large amounts, dopamine creates feelings of pleasure, as well as motivation to repeat a specific behavior, even if harmful. Risk factors for drug addiction include: psychiatric illnesses, drug availability, socio-economic status, childhood abuse, age at first exposure – and genetics, Day said. He said a number of addiction studies involving twins have been conducted and show that there is a heritability factor: 54 percent for heroin and opiates, up to 79 percent for marijuana, up to 81 percent for cocaine and 79 percent for hallucinogens. “Genetics contributes to addiction but having a gene variance doesn’t mean you’ll become addicted,” Day said, adding that gene variations reside in the brain’s regulatory areas. He said the waves of addiction include drug delivery, which can result in a change in gene expression, “and then these genes can turn on other receptors.” The Alice McLean Stewart Endowed Fund for Addiction Education was established in 1994 by Alice McLean Stewart to develop and understanding and spread knowledge of alcoholism and other chemical abuse elements through this lecture series.