Perhaps the gene that causes schizophrenia has been discovered.
http://www.cnn.com/2016/01/28/health/schizophrenia-a-genetic-cause/index.html
Certainly seems to run in my family. You should meet my cousin, the beer drinking, Ramadan bacon eating Muslim. At least grandma was catatonic. She might have lain in bed for months at a time but the family didn't wonder if s-he was going to try to fly to Syria....