Paranoid personality disorder (PPD) is a mental illness characterized by paranoid delusions, and a pervasive, long-standing suspiciousness and generalized mistrust of others. People with this personality disorder may be hypersensitive, easily insulted, and habitually relate to the world by vigilant scanning of the environment for clues or suggestions that may validate their fears or biases. They are eager observers. They think they are in danger and look for signs and threats of that danger, potentially not appreciating other interpretations or evidence.They tend to be guarded and suspicious and have quite constricted emotional lives. Their reduced capacity for meaningful emotional involvement and the general pattern of isolated withdrawal often lend a quality of schizoid isolation to their life experience. People with PPD may have a tendency to bear grudges, suspiciousness, tendency to interpret others actions as hostile, persistent tendency to self-reference, or a tenacious sense of personal right. Patients with this disorder can also have significant comorbidity with other personality disorders, such as schizotypal, schizoid, narcissistic, avoidant and borderline. Causes
A genetic contribution to paranoid traits and a possible genetic link between this personality disorder and schizophrenia exist. A large long-term Norwegian twin study found paranoid personality disorder 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.
He also observed a contradiction in these personalities: on the one hand, they stubbornly hold on to their unusual ideas, on the other hand, they often accept every piece of gossip as the truth. Kraepelin also noted that paranoid personalities were often present in people who later developed paranoid psychosis. Subsequent writers also considered traits like suspiciousness and hostility to predispose people to developing delusional illnesses, particularly "late paraphrenias" of old age.Following Kraepelin, Eugen Bleuler described "contentious psychopathy" or "paranoid constitution" as displaying the characteristic triad of suspiciousness, grandiosity and feelings of persecution. He also emphasized that these peoples false assumptions do not attain the form of real delusion.Ernst Kretschmer emphasized the sensitive inner core of the paranoia-prone personality: they feel shy and inadequate but at the same time they have an attitude of entitlement. They attribute their failures to the machinations of others but secretly to their own inadequacy. They experience constant tension between feelings of self-importance and experiencing the environment as unappreciative and humiliating.Karl Jaspers, a German phenomenologist, described "self-insecure" personalities who resemble the paranoid personality. According to Jaspers, such people experience inner humiliation, brought about by outside experiences and their interpretations of them. They have an urge to get external confirmation to their self-deprecation and that makes them see insults in the behavior of other people. They suffer from every slight because they seek the real reason for them in themselves.