Is It Disease or Delusion? U.S. Takes on a Dilemma - New York Times

Is It Disease or Delusion? U.S. Takes on a Dilemma - New York Times: "Researchers have found that delusions like this can be passed from primary patients to secondary ones, usually susceptible family members or close associates. Psychiatrists call this phenomenon folie a deux.

In one remarkable case, a woman convinced her husband that neighbors were shooting at her with lasers. In another, an elderly woman convinced her live-in sister that they were both being attacked by bugs.

“Parasitosis is a classic form of shared delusion,” said Dr. Mary Seeman, an emeritus professor of psychiatry at the University of Toronto. “Skin disease is perfect for it. A person gets a rash or something, then the ‘disease’ spreads through any shared space in which there is close contact.”

But the Internet may have greatly altered the dynamics of folie a deux. In the connected, always-on world, separation is no longer so easy, and delusions may be shared and supported far beyond the confines of the home or workplace."