Exposure to infection and immune stress in the womb increases the likelihood of alcohol misuse in adulthood, according to a new Washington State University study published in the journal Psychopharmacology. The findings suggest that prenatal antioxidant treatment may reduce this risk and provide insight into how early biological stress shapes addictive behaviors.
The Two-Hit Model of Addiction
Researchers led by Angela M. Henricks, an assistant professor in the WSU Department of Psychology, examined how maternal immune activation—the body’s response to infection, stress, or inflammation—affects the desire to drink alcohol later in life. Using a well-established animal model, pregnant rats were exposed to a synthetic substance that mimics a virus. Offspring exposed to prenatal immune stress showed increased motivation to self-administer alcohol in adulthood, but only if they had also been exposed to alcohol in adolescence. This supports a “two-hit” model of addiction risk, in which early immune stress interacts with later life experiences to raise the likelihood of a use disorder.
Some pregnant rats received the antioxidant N-acetylcysteine (NAC) before and after immune activation, while controls received saline. Prenatal antioxidant treatment suppressed the increased alcohol-seeking response, suggesting that oxidative stress—which occurs when there is too much DNA-damaging oxidation in cells—may be important in linking prenatal infection to addiction risk. “This suggests that oxidative stress is significantly contributing to why prenatal infection might be a risk factor,” Henricks said.
Sex-Specific Effects and Public Health Impact
The study revealed sex-specific effects: male offspring were more sensitive to the impact of prenatal infection and showed the clearest response to antioxidant treatment, while females did not show the same increase in alcohol-seeking behavior. This underscores the importance of considering biological sex in addiction research and may explain why males are more susceptible to neurodevelopmental and substance use disorders.
The research addresses a significant public health concern: excessive drinking causes an estimated 178,000 deaths per year and has an annual cost of $249 billion in lost workplace productivity, health-care expenses, and other factors, according to the U.S. Centers for Disease Control.
This article is an AI-assisted summary. All facts and figures are drawn from the original report: https://news.wsu.edu/press-release/2026/02/19/prenatal-infection-increases-risk-of-heavy-drinking-later-in-life/