Children's ADHD Risk Linked to Mothers' Use of Common OTC Pain Reliever

New research has linked prenatal exposure to a common over-the-counter pain reliever, acetaminophen, with a higher risk of ADHD in children. The study, published in Nature Mental Health, examined blood samples from 307 pregnant Black women during their second trimester and found that the presence of acetaminophen increased the likelihood of their children developing ADHD by threefold. Researchers also analyzed placental samples post-delivery, revealing inflammation markers and DNA changes tied to the immune system pathways, which may contribute to the disorder.

Lead author Brennan Baker from Seattle Children’s Research Institute stressed the importance of these findings, suggesting immune system disruptions as a possible mechanism. Dr. Ryan Sultan of Columbia University, not involved in the study, described the results as "important and concerning" while advising pregnant women to use acetaminophen sparingly and only when medically necessary.

Despite the alarm bells, experts caution against outright panic. The study’s limitations—such as its small sample size and focus on Black mothers in the South—mean it cannot conclusively prove causation. Baker acknowledged these challenges, noting attempts to control for confounding factors like family mental health history, socioeconomic status, and prenatal exposure to tobacco and alcohol.

Conflicting research further complicates the narrative. A Swedish study of 2.5 million children found no link between acetaminophen and ADHD, autism, or intellectual disability, while a Taiwanese study supported the association. Many prior studies relied on self-reported medication use, which can underestimate exposure.

ADHD, affecting 1 in 9 U.S. children, is a multifactorial condition influenced by genetics, environment, and other prenatal factors. With 80% of pregnant women taking medication, acetaminophen remains a go-to for pain and fever. However, this study adds to growing concerns about its safety during pregnancy—a dilemma for expectant mothers needing relief.

Funded partly by the National Institutes of Health, the research raises a tough question: How should we balance medical necessity against potential long-term risks? Manufacturers of acetaminophen-containing products declined to comment.