Phenomenon where groups of people experience similar physical symptoms with no identifiable medical cause, discussed in cases from Le Roy, NY and among law enforcement with fentanyl exposure.
"Eventually, doctors concluded that it was a mass psychogenic illness, and that there were no real causes for the symptoms they were experiencing. What's interesting is that outside of the Havana syndrome and Fentanyl cases, the vast majority of mass psychogenic illness cases are with girls and women"