An early magazine advertisement for Merck's breakthrough asthma and allergy medicine, Singulair, featured a happy child, hanging upside-down from a tree. Asthmatic kids could now breathe easier, the text assured, and side effects were usually mild" and "similar to a sugar pill." When the drug launched in 1998, its label said the drug's distribution in the brain was "minimal," with no mention of psychiatric side effects. Merck's early safety claims later faced intense scrutiny amid reports over two decades that patients, including many children, had died by suicide or experienced neuropsychiatric problems after taking the drug. The FDA in 2020 ordered its most serious warning, known as a "black box," on Singulair's label. And Merck now faces a raft of lawsuits alleging it knew from its early research that the drug could impact the brain and that it minimized the potential for psychiatric problems in statements to regulators. The lawsuits cite the research of Julia Marschallinger, a cell biologist who has studied the drug along with colleagues at the Institute of Molecular Regenerative Medicine in Austria. That team found in 2015 that the drug's distribution into the brain was more significant than its label described. In its original patent for Singulair, Merck cited other applications for the drug, beyond asthma and allergies, including as a treatment for "cerebral spasm," a neurological condition. Lawsuits filed against Merck cite this 1996 patent as evidence of Merck's knowledge of the drug's potential brain impacts.