MDL Judge Will Consider New Expert Evidence That Tylenol Causes ADHD in Lawsuits Filed After Jan. 12, 2024

The U.S. District Judge presiding over all Tylenol ADHD and autism lawsuits brought in the federal court system, most of which were dismissed late last year after the Court found that the plaintiffs were unable to provide admissible expert witness testimony to support their claims, is allowing families who filed their coplaint after that decision to present arguments that new evidence linking Tylenol and ADHD should be allowed to move forward.

For decades, Tylenol (acetaminophen) has been widely used by pregnant women, largely due to the widespread belief that it is safe for unborn children. However, a growing number of lawsuits have been filed in state and federal courts in recent years, each raising similar allegations that drug makers failed to adequately warn pregnant women and the medical community about the growing evidence that prenatal exposure toTylenol causes autism or ADHD.

Given common questions of fact and law over the adequacy of the Tylenol pregnancy warnings, the U.S. Judicial Panel on Multidistrict Litigation (JPML) established coordinated pretrial proceedings last year, centralizing all claims brought throughout the federal court system before U.S. District Judge Denise Cote in the Southern District of New York, as part of a federal multidistrict litigation (MDL).

In December, Judge Cote issued an opinion excluding plaintiffs’ expert witnesses from testifying about the Tylenol pregnancy side effects, after determining the scientific approaches and studies used were not sound enough to allow the opinions to be presented to a jury.

The move has been seen as spelling the end of the Tylenol litigation in the federal court system, since it left plaintiffs without required expert testimony to prove Tylenol caused developmental disorders when women took the painkiller during pregnancy.

After the decision, plaintiffs were given time to show cause why no summary judgment should be issued dismissing their cases, but about 500 of the cases were dismissed in February. However, the ruling does not apply to Tylenol ADHD and autism lawsuits being pursued in state courts nationwide, and families who have filed complaints since the ruling have argued they should be allowed to present new evidence.

New Tylenol ADHD Lawsuits Rely on New Evidence

In February, five plaintiffs, who all filed their cases after January 12, indicated that they intend to use a different expert witness and research that was not presented in the earlier cases. The testimony will be submitted by Dr. Roberta B. Ness, who indicates that acetaminophen exposure during pregnancy can cause ADHD.

In a court order (PDF) issued on March 15, Judge Cote ruled that plaintiffs who filed Tylenol ADHD lawsuits after January 12, known as the Mota plaintiffs, will be able to present arguments to the court about whether the Ness report is based on sufficiently reliable and sound sciece to allow it to be admissible at trial, which is needed to keep their cases from being dismissed.

The court expects to receive briefings from plaintiffs and defendants on June 6, and is expected to decide whether the testimony is enough to keep the litigation alive sometime this summer.