Study Identifies Gene Linked to Alcohol Dependence

Impact of Alcohol Consumption

A recent study highlights the gene most strongly associated with alcohol dependence, shedding light on other genetic influences and relationships. Alcohol abuse stands as one of the primary causes of death and disease globally, with one in every twenty deaths attributed to alcohol consumption. Alcohol dependence is recognized as a serious psychiatric disorder, classified in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). It is marked by excessive drinking patterns, where individuals persist in their behavior despite significant health and well-being repercussions. Key characteristics include heightened alcohol tolerance and the emergence of withdrawal symptoms. Approximately 12% of alcohol consumers are estimated to fall under this diagnosis, yet only about 25% of these individuals are believed to receive treatment in the United States.

Research Overview

The study, published in Nature Neuroscience, investigates the heritability of alcohol dependence. Previous estimates suggested that this disorder was moderately heritable. Conducted by the Substance Use Disorders working group of the Psychiatric Genomics Consortium, the research delves into the genetic aspects of alcohol dependence, while also recognizing the role of environmental factors and their interplay with genetics.

Study Details

The research included 14,904 patients diagnosed with alcohol dependence and 37,944 healthy controls. The findings identified the ADH1B gene as significantly associated with alcohol dependence. This gene plays a crucial role in alcohol metabolism, influencing how the body converts alcohol into acetaldehyde, a compound responsible for the unpleasant sensations that can accompany drinking. Variants of the ADH1B gene affect the rate of this conversion, making certain individuals less likely to continue excessive drinking.

Broader Genetic Links

The study also revealed that genetic associations linked to alcohol use disorder correspond to other psychiatric conditions, including depression, schizophrenia, and ADHD, as well as the usage of other substances like cigarettes and marijuana. This raises questions about whether these associations are specific to alcohol dependence or are related to the broader consequences of these disorders.

Population Differences

The research identified genetic differences between European descendants and African American populations regarding the ADH1B gene, suggesting that different variants impact risk levels in these groups. Additionally, the genetic factors leading to alcohol dependence differ from those that merely promote heavy drinking.

Conclusion and Future Research

While this extensive study indicates a relationship between the ADH1B gene and alcohol use disorders, the strength of this association is relatively modest. Much of the variance is attributed to the interaction of various genes and environmental factors. The researchers emphasize the necessity for larger studies to further explore the diverse associations of this gene. More targeted investigations are required to understand population-specific differences and their connections to other psychiatric disorders.

Written by Maor Bernshtein
Reference: Walters, R. K., Polimanti, R., Johnson, E. C., Mcclintick, J. N., Adams, M. J., Adkins, A. E., … Agrawal, A. (2018). Transancestral GWAS of alcohol dependence reveals common genetic underpinnings with psychiatric disorders. Nature Neuroscience, 21(12), 1656-1669. doi:10.1038/s41593-018-0275-1