Why does one person who tries cocaine get addicted, while another might use it and then leave it alone? Why do some people who kick a drug habit manage to stay clean, while others relapse? And why do some families seem more prone to addiction than others?
The road to answering these questions may have a lot to do with specific genetic factors that vary from individual to individual, a new study in rats suggests.
Of course, an animal study can’t explain all the factors that contribute to differences in addiction among humans. But the findings reveal new information about the roles played by both inherited traits and addiction-related changes in the brain.
The study was published in the Proceedings of the National Academy of Sciences by a University of Michigan Medical School team.
It’s the first time scientists have shown in selectively bred animals that the propensity for addiction is linked to differences in expression of genes for specific molecules in a specific brain region. It’s also the first demonstration that a DNA tag called an epigenetic marker can predispose an individual to addiction and relapse.