The researcher who three decades ago published groundbreaking findings that helped establish a genetic link to addiction offered a National Conference on Addiction Disorders (NCAD) East audience a dose of optimism about genetic testing's potential to generate personalized approaches to substance use treatment.
“Can you alter the environment enough to change gene expression? We think you can,” said Kenneth Blum, PhD, chief scientific officer of Austin, Texas-based Geneus Health. Geneus is heading the marketing of the Genetic Addiction Risk Score (GARS) test, a composite assessment of the presence of gene variants shown to be associated with risk for addiction to specific substances and engagement in other risk behaviors.
Use of the simple GARS cheek swab test, which is not yet covered by insurance plans, has been somewhat slow to gain momentum among addiction treatment centers, though some early adopters have said the knowledge gathered from it can help patients gain insight into their illness and identify tailored treatment strategies. Others see a test such as this as having applications ranging from alerting pain physicians to the potential for opioid dependence to signaling to parents that a specific prevention approach might be ideal for their children.
Although Blum has been at the center of landmark findings in genetics, he does not at all diminish the equally important role environmental factors play in the course of addiction and in its treatment. His co-presenter for the Aug. 15 afternoon plenary session at the Baltimore conference, Florida treatment professional Lyle Fried, reinforced the interrelationship of genes and environment when he said, “Genetics loads the gun and life pulls the trigger.”
Fried said he first learned of Blum's work at a past NCAD meeting in St. Louis and helped put GARS into practice at the now-closed The Shores Treatment & Recovery in Port St. Lucie, Fla. Fried now works in professional relations at Transformations Treatment Center in Delray Beach, where leaders have been exploring use of the test as a way to help military veterans and first responders gain insight into their behavioral health issues.
For treatment center leaders who would ask why a facility would want or need to offer a genetic test to someone who is already enrolled in its treatment program, Fried said the results could confirm findings from assessments and point toward viable clinical strategies. Personalized nutritional supplements are one of the prominent components of treatment approaches derived from findings in genetic testing.
Role of dopamine
Blum added a touch of humor to heavy science in explaining the role of dopamine, which he called “a culprit in all addictive behaviors.” (His affinity for dopamine's importance even led him to write a song about the neurotransmitter.) In the mid-1990s he introduced to the field the term “reward deficiency syndrome” to describe a relative failure of the dopaminergic system, which plays a major part in brain reward mechanisms.
Blum in the 1990s published groundbreaking research that identified a variant in the dopamine D2 receptor gene (the A1 allele) that more than one-third of the U.S. population carries. Those numbers are substantially higher for subgroups such as African-Americans (50%) and Native Americans (85%). With the presence of that allele, “You have 40% fewer dopamine receptors in the brain,” Blum said.
GARS tests for risk alleles on 10 genes in all, including the D2 gene, offering a total risk score ranging from a low of 1 to a high of 22. Fried said that in his work he has seen scores of anywhere from 3 to 10. But, he added, it is particularly useful that the test spells out substance-specific risk as well as risk for other potentially problematic behaviors such as gambling and adventure seeking.
Blum expressed hope that genetic testing could lead to treatment strategies more lasting than, for example, using an opioid (e.g., buprenorphine) to treat opioid addiction. He characterized those approaches more as a tool to get someone going on the path to recovery. Through use of prevention and lifestyle intervention approaches, the bigger-picture question issue becomes, “Can we do something to bring about dopamine homeostasis?” he said.