Increasing social media use by adolescents has amplified a strange phenomenon--mass hysteria, or as it is called now, Mass Psychogenic Illness (MPI). Instances of mass hysteria are recorded as far back as medieval times and earlier. Now, through the internet, outbreaks can spread worldwide. Think it's odd? Interested? Read these articles, which use a recent outbreak as an example (click to link):

[Best article! (Psychology Today): research on the relationship of MPI to social media use]

[Article on a modern instance of Mass Psychogenic Illness]

[Article on social media spreading Mass Psychogenic Illness worldwide]

[What is Mass Psychogenic Illness? (Wikipedia)]