In a significant legal development, a federal judge has dismissed the remaining lawsuits against Kenvue and several retailers, including Walgreens and Walmart, over claims that Tylenol causes Attention Deficit Hyperactivity Disorder (ADHD) in children whose mothers used the medication during pregnancy. The ruling, issued on August 20, 2024, marks the end of a contentious legal battle that began in early 2022.
U.S. District Judge Denise Cote in Manhattan determined that the cases could not proceed without key expert testimony, which she had previously rejected. This decision aligns with the stance of the U.S. Food and Drug Administration (FDA) and leading medical organizations, which have consistently stated that scientific evidence does not support a causal link between acetaminophen use during pregnancy and ADHD.
The litigation, centralized before Judge Cote in October 2022, initially included approximately 550 cases alleging that Tylenol and its generic versions caused ADHD or Autism Spectrum Disorder (ASD). These cases were dismissed in December 2023 when Judge Cote ruled that the plaintiffs' expert witnesses had not used sound scientific methodology in their analyses.
Despite this setback, plaintiffs continued to file new lawsuits, focusing solely on the ADHD claims and offering a new expert witness. However, Judge Cote rejected this expert as well, leading to the dismissal of the remaining 58 ADHD cases as of August 1, 2024.
Kenvue, formerly Johnson & Johnson's consumer health division and now an independent company since 2023, welcomed the court's ruling. A spokesperson stated, "The court's ruling continues to align with the position of the U.S. Food and Drug Administration and leading medical organizations that have thoroughly evaluated this — the science does not support causation."
It's worth noting that acetaminophen, Tylenol's active ingredient, has been widely used for decades. The FDA approved it for over-the-counter use in 1960, and it remains the most commonly used medication for pain and fever during pregnancy. The first study suggesting a potential link between acetaminophen use during pregnancy and ADHD was not published until 2014, more than 50 years after the drug's introduction to the market.
The legal proceedings highlighted the complex nature of establishing causation in medical liability cases. Judge Cote criticized the plaintiffs' experts for their "unstructured approach" that allowed for "cherry-picking" and a "results-driven analysis." This underscores the importance of rigorous scientific methodology in legal contexts involving medical claims.
"The plaintiffs seize on fragments from Dr. Faraone's extensive writings and prior statements and misleadingly portray those fragments."
This ruling serves as a reminder of the ongoing debate surrounding the safety of common medications during pregnancy and the challenges in proving causation for complex neurodevelopmental disorders like ADHD, which affects approximately 5% of children worldwide.
As the legal chapter closes on this multidistrict litigation, it leaves behind important questions about the intersection of science, law, and public health. The case also highlights the evolving nature of corporate responsibility, as exemplified by Kenvue's position as a newly independent company facing litigation related to products developed under its former parent company, Johnson & Johnson.