“Can mass hysteria now spread even faster because of Facebook? Great writing, interesting hypothesis.” Science writer and blogger Kyle Hill, linking to a September 11, 2013, article in The Atlantic that suggests Facebook and social media could have contributed to the comeback of mass hysteria episodes in the United States. According to author Laura Dimon, “It starts with conversion disorder, when psychological stressors, such as trauma or anxiety, manifest in physical symptoms. The conversion disorder becomes ‘contagious’ due to a phenomenon called mass psychogenic illness, historically known as ‘mass hysteria,’ in which exposure to cases of conversion disorder cause other people—who unconsciously believe they’ve been exposed to the same harmful toxin—to experience the same symptoms.” New Zealand sociologist Robert Bartholomew, who has studied mass hysteria for 20 years, suggests that social media could be playing a role in its resurgence.

Scientific American Blogs, September 15, 2013.