A genetic contribution to<unk>  traits and a possible genetic link between this personality disorder and schizophrenia exist. A large long-term Norwegian twin study found<unk>  to be modestly heritable and to share a portion of its genetic and environmental risk factors with the other cluster A personality disorders, schizoid and schizotypal. Psychosocial theories implicate projection of negative internal feelings and parental modeling. Cognitive theorists believe the disorder to be a result of an underlying belief that other people are unfriendly in combination with a lack of self-awareness.
Paranoid personality disorder
Delusional disorder
Histrionic personality disorder
Dependent personality disorder
Depressive personality disorder
Organic personality disorder
Haltlose personality disorder
Borderline personality disorder