The cause of personality disorders is unknown. However, genes and childhood experiences may play a role.
https://medlineplus.gov/personalitydisorders.html
Medline can go soak its disease mongering industry corrupted head.
There are NO genetic factors involved in people's moods, thoughts or behaviors.
The Genetics of Schizophrenia
http://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.0020212Schizophrenia, along with all of Psychiatry's other BS Diagnoses is a Social Construct used to Profitably marginalize, demonize, and Control people whom other people may find offensive, PERIOD.
THIS, is what Psychiatry's antipsychotic drugs do to the brains of children (and adults).

Again and again, despite Industry pronouncements from these Quacks that School Shootings and Workplace Violence are NOT THEIR Fault, contradicting voluminous evidence to the contrary, get down with the ridiculousness of their defensive argument.
SSRI Stories.org deals with SSRI antidepressant problems
https://ssristories.org/all-posts/The current paradigm, for decades, is that moods, thoughts and behaviors are produced by imbalances of brain chemicals or genetic predispositions.
However, they have Never proven any of those models, claiming instead that They Will, given Time, because those differences are so tiny that they haven't quite found them yet, but they will. Just keep the Research Grant Money Coming.
Psychiatry's Manufacture of Consent, The Chemical Imbalance Theory and The Antidepressant Explosion
http://psychroaches.blogspot.com/2014/06/psychiatrys-manufacture-of-consent.htmlThe Crumbling Pillars of Behavioral Genetics
http://www.councilforresponsiblegenetics.org/GeneWatch/GeneWatchPage.aspx?pageId=384NOW, Psychiatry can't identify ANY Brain Chemical Abnormalities or Genetic Combinations Causing Behaviors which Psychiatry calls an 'Illness' because they're too tiny.
BUT, The Homicides and Suicides Psychiatry DOES Cause with their Drugs, Isn't Their Fault, IN SPITE of the MASSIVE, easily and well recorded/photographed deterioration of the human brain Psychiatry's Drugs DO CAUSE. See the jpg again.