Do addictions share common genetic origins with other behavioral disorders?

A genetic analysis conducted on over two million people reveals that the risks of substance addiction do not depend solely on factors specific to each product. Disorders related to drug, alcohol, or tobacco use often occur together and share a large part of their genetic origin with other behaviors marked by a lack of control, such as hyperactivity, childhood behavioral disorders, or risk-taking behaviors in adulthood. These links suggest that genetic vulnerability to addictions is largely explained by a broader predisposition to impulsivity and behavioral disinhibition.

Researchers have identified that nearly 80% of the genetic influences on alcohol-related disorders and up to 70% for other addictions are common across multiple substances and behaviors. This means that a person genetically predisposed to alcoholism also has an increased risk of developing other forms of addiction or behavioral disorders. However, each substance also retains a portion of genetic risk that is specific to it, related in particular to how the body metabolizes or reacts to that substance. For example, certain genes specifically influence alcohol dependence by acting on enzymes that break down this molecule, while other genes affect sensitivity to nicotine by altering brain receptors.

By studying these various disorders simultaneously, scientists have been able to discover new genes involved in addictions, some of which had never been associated with these problems before. This comprehensive approach has also helped to better understand the underlying biological mechanisms. The identified genes are often active in brain areas related to neuron communication, molecule transport within cells, or mood regulation. Some of these genes are even targets of medications already used to treat addictions, such as naltrexone for alcoholism or varenicline for smoking.

The study also shows that the genetic factors common to addictions and behavioral disinhibition explain a significant portion of the risk of developing these disorders. On the other hand, genetic variations specific to each substance allow for a more precise prediction of the risk of addiction to that particular substance. Thus, a person may have a general predisposition to addictions, as well as specific vulnerabilities depending on the substance.

These findings highlight the importance of studying addictions not in isolation, but by considering their links with other behavioral disorders. Such an approach could improve prevention and treatment by targeting both common mechanisms and those specific to each substance. It also paves the way for more precise genetic screening tools, capable of assessing the overall risk of addiction as well as individual sensitivities.

References

Origin of the Study

DOI: https://doi.org/10.1038/s44220-026-00608-6

Title: Multivariate genetic analyses of 2.2 million individuals reveal broad and substance-specific pathways of addiction risk

Journal: Nature Mental Health

Publisher: Springer Science and Business Media LLC

Authors: Holly E. Poore; Chris Chatzinakos; Brittany Leger; Jean Gonzalez; Travis T. Mallard; Fazil Aliev; Alexander Hatoum; Irwin D. Waldman; Sandra Sanchez-Roige; Abraham A. Palmer; K. Paige Harden; Danielle M. Dick; Peter B. Barr