HMN 2026: What is the possible primary route for the transmission of alcohol use disorder within families

Brain activity related to how young adults value reward appears to be linked to longer-term drinking patterns, according to a study of college students with family histories of alcohol use disorder (AUD). The findings raise the possibility of precision medicine—individualized interventions to modify risk—for young people vulnerable to addiction. A family history of AUD increases the risk of alcohol-related problems, including AUD, threefold or fourfold.

While the neurocognitive routes by which familial risk is transmitted are not well understood, some research implicates delay discounting: a preference for immediate rewards over larger, more distant ones. People whose close biological relatives have alcohol use problems are more prone than others to steeper delay discounting, meaning they tend to have a stronger preference for immediate rewards. This suggests an inherited or environmental vulnerability to impulsive decision-making, potentially contributing to riskier alcohol use trajectories.

For the study in Alcohol, Clinical and Experimental Research, U.S. investigators explored whether young adults with family histories of AUD exhibited differences in neural mechanisms related to delay discounting and whether these differences could explain their increased risk for AUD.

They worked with 165 college students ages 18 and 19, conducting functional MRI (fMRI) to assess delay discounting by observing brain activity while participants made hypothetical choices between receiving different amounts of money immediately or in the future. The participants also underwent drug and alcohol testing and filled out validated questionnaires on their substance use behaviors and other factors, with annual follow-up surveys over three years.

During the fMRIs, participants with family histories of AUD exhibited elevated activation in the nucleus accumbens, a brain region involved in reward valuation and motivation. This heightened activation predicted future drinking and was linked to steeper alcohol use trajectories compared with participants without family histories of AUD.

The findings add to evidence of the role of the nucleus accumbens in addiction risk and substance use disorders. Its reward circuitry may be a major pathway through which a family history of AUD promotes risky drinking, biasing vulnerable people toward immediate reward, including alcohol use.

Brain imaging may predict the risk of alcohol misuse more successfully than behavior can and points to the possibility of individualized treatment to modify people’s reward sensitivity or responses. Other neural systems may also be involved in transmitting AUD risk, with their roles and influences varying across developmental stages and contexts.

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