Problematic alcohol use—that is, heavy drinking, or drinking that is accompanied by unpleasant consequences—tends to increase as people go through late adolescence, peaking at about age 22 or so and then declining as they grow older.
Problematic alcohol use (PAU) is the main source of death and disability around the world. Even though genome-wide association studies have distinguished PAU risk genes, the genetic architecture of this trait isn’t completely comprehended.
A genome-wide analysis of a total of 435,563 European-ancestry people has identified 29 independent risk variants that are associated with problematic drinking. 19 of them are novel variants.
Scientists looked for shared genetic variants among those who met the criteria for problematic alcohol use, including alcohol use disorder and alcohol use with medical consequences. These disorders are significant contributors to a wide variety of medical problems worldwide.
Scientists detected 19 novel, unknown independent genetic risk factors for problematic alcohol use, whereas they confirmed ten previously identified risk factors.
The meta-analysis of biobank data also included information on genetic risk factors for several psychiatric disorders. This information allowed researchers to study shared genetic associations between problematic drinking and disorders such as depression and anxiety.
Scientists found that the genetic heritability of these variants was enriched in the brain and evolutionarily conserved regulatory regions of the genome, attesting to their importance in biological function.
Scientists then used the Mendelian randomization technique to determine how one genetically influenced trait affects another genetically linked trait.
Yale’s Hang Zhou, an associate research scientist in psychiatry and lead author of the study, said, “This gives us ways to understand causal relations between problematic alcohol use traits such as psychiatric states, risk-taking behavior, and cognitive performance.”
Gelernter said, “With these results, we are also in a better position to evaluate the individual-level risk for problematic alcohol use.”