Researchers at Ohio State University believe they’ve found a genetic variant (characterized by one or both of two identified, tiny gene mutations) that is associated with a more than three times increase in susceptibility to severe cocaine abuse with the risk of fatal overdosing, compared to non-carriers of the genetic variant. (ScienceDaily)
This genetic variant was most common among white people with nearly one in five carrying the genetic variant. Among this group of people, one or both of the genetic variants were found in more than 40 percent of the autopsy brain samples from those known to abuse cocaine. This is compared to only 19 percent of those who lived drug-free and contained one or both of the genetic variants.
It was found that this genetic variant, one or both in combination, affect how dopamine functions in the brain. As we’ve discussed before, dopamine is a key neurotransmitter in the reward center of the brain, as well as numerous, regulatory functions of the central nervous system. Previous studies have shown that cocaine blocks dopamine’s reabsorption, leaving the chemical outside the brain cells and thus creates an artificial “feel-good” sensation.
This study found that in people who carry this genetic variant, the “function of a gene responsible for transmitting dopamine signals in the brain is altered” (Medical News Today). This led scientists to believe that this alteration can send neurotransmitters into a vicious cycle, including the development of cravings for an artificial substance, such as cocaine, that can maintain elevated levels of dopamine in the brain.
The study will soon be published in Neuropsychopharmacology. It has further opened the door to more questions about the involvement of the variant in initial use of the drug, level of cravings, and strength of the overall effect of the trait. It also suggests the need to explore how this variant could affect treatment for other psychiatric disorders involving dopamine.
