The Atlantic reports that US intelligence agencies are not united on the idea that Havana syndrome wasn’t based on a real attack. From the article though it doesn’t seem like there’s any new evidence, only a struggle over how much to believe alleged victims. 

My question is, is there anything like this that has happened before? I know there’s mass insanity sometimes in history, like in the Middle Ages or among third world tribesmen. But have we ever seen modern people in a professional community all develop the psychosomatic illness with symptoms this serious?