A judge has barred expert witnesses from testifying that Johnson & Johnson spin-off Kenvue's painkiller Tylenol can cause autism if mothers take it during pregnancy, finding that they failed to support their conclusions with scientific evidence. The ruling on Monday by U.S. District Judge Denise Cote in Manhattan federal court likely means the end of a consolidated mass tort litigation of about 500 lawsuits over the popular over-the-counter drug, unless plaintiffs get it reversed on appeal. Cote, in a 148-page ruling, found that none of the five expert witnesses proposed by the plaintiffs had offered a sound scientific methodology to support their opinion that Tylenol's active ingredient, acetaminophen, could cause autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD).