Cluster A Disorders

Paranoid personality disorder (PPD) is a Cluster A personality disorder. Paranoid personality disorder is a clinically well-recognized disorder that has not been the object of a great deal of investigation. Although noted in the writings of psychiatrists since the late 1800s, the condition was first called paranoid personality by Kraepelin in 1921 (Akhtar, 1990).

The hallmark criteria regarding paranoid personality disorder (PPD) are distrust and suspicion of others such that others are seen as purposefully attempting to harm one in some way without any evidence to suggest this is the case. Individuals with paranoid personality disorder also may be very critical of others, argumentative, and rigid in beliefs, again stemming from harboring unwarranted suspicions about people around them. This behavior often leads to problems with relationships, both personal and in the workplace.

Diagnosing Paranoid Personality Disorder

Figure 1. A person with paranoid personality disorder is suspicious and mistrustful of others but does not experience delusions or hallucinations consistent with schizophrenia.

Paranoid personality disorder (PPD) is characterized by a general suspicion and distrust of others that presents with at least four or more of the following:

• suspicion that others are exploiting or harming them
• a preoccupation with doubting the loyalty of friends
• a reluctance to share information with others for fear it will be used against them
• views harmless comments or events as threatening or demeaning
• holds grudges
• quick to defend or attack perceived threats to their reputation or character
• has recurrent suspicions about the infidelity of a partner^[1]

Paranoid personality disorder must be diagnosed to the exclusion of schizophrenia, or any other psychotic disorder including psychosis in the context of a mood disorder.

Comorbidity

Individuals with paranoid personality disorder appear to have an increased likelihood of developing depression, agoraphobia, obsessive-compulsive disorder, and alcohol or substance abuse or dependence. With regard to comorbid personality disorders, there is some variation in the literature. Generally though, it has been suggested that in clinically based samples, over 75% of patients who met paranoid personality disorder criteria also met criteria for other personality disorders: the most common were found to be schizotypal and narcissistic.

One area of research is the possible relationship of post-traumatic stress disorder (PTSD) with personality disorders, with the strongest association with paranoid personality disorder, specifically paranoid personality disorder.^[2] This suggests a possible link between trauma during early events in life and subsequent paranoid behavior and mistrust.

Another area that has received some attention is the relationship of violence to paranoid personality disorder. Paranoid cognitive personality style was found to increase the risk of violence in subjects with personality disorders, particularly schizophrenia spectrum disorders (Nestor, 2002). Estimates of the prevalence of paranoid personality disorder range from 2.3% to 4.4% in the United States.^[3]

Etiology

There is no known cause of PPD, but researchers believe it is caused by a combination of biological, psychological, and social factors. Genetics play a role in contributing to paranoid traits and there is also a possible genetic link between PPD and schizophrenia. Using data from the Roscommon family study, an epidemiologic study conducted in Ireland, it was discovered that biological relatives of those with schizophrenia had a significantly higher amount of paranoid personality disorder compared with relatives of controls (Kendler et al. 1993).

Figure 2. Some theories argue that PPD stems from negative parental modeling.

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.^[4]

Psychosocial theories argue that the disorder stems from early trauma or childhood abuse, possibly coming from the projection of negative internal feelings or 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.

As with other disorders, cultural factors must be taken into account in diagnosing this disorder. There are some groups that might, for reasons of maltreatment, language barriers, and unfamiliarity to the mainstream society, display what could be labeled paranoid traits. In an epidemiologic study recently completed on personality disorders, Black, Hispanic, and Native American people were at greater risk for having paranoid personality disorder than White people (Grant et al. 2004). Also, according to the same study, paranoid personality disorder was more common among younger people (ages 18–29), those with lower incomes, and those who were divorced or never married. Some of these findings are not surprising, taking into account the nature of paranoid personality disorder. However, this does bring up the question of which came first: are some paranoid traits the result of maltreatment by others due to socioeconomic status (SES), race, etc., or does the disorder contribute to, for example, the inability to succeed professionally or remain in a relationship? There appears to be a combination of both, which can contribute to complications in diagnosing the disorder.

Course and Prognosis

PPD can be noted first in childhood; symptoms observed include solitariness, social anxiety, and odd thoughts and language. Kids who are bullied, socially unaccepted, or even abused, may be more prone to PPD. There is not a lot of data regarding the course and prognosis of the disorder. This is likely due to the fact that as it is a personality disorder, it tends to be stable over adult life and although it can cause interpersonal problems, does not often require treatment. It has been observed that the course of the disorder rarely worsens or goes into remission (Akhtar, 1990).

Treatment

There is no specific treatment or medication for PPD. When existing in conjunction with other personality disorders, i.e., borderline personality disorder, treatment may be sought, but that is primarily due to symptoms experienced in other personality disorders. There is some data on the effectiveness of day treatments for patients with personality disorders in general (Karterud et al. 2003). Treatment results, although effective for some personality disorders (i.e., borderline), were the poorest for those with paranoid, schizoid, and schizotypal personality disorders.