What is Paranoid Personality Disorder?

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Understanding Personality Disorder

It’s hard enough defining what personality is without attempting to discuss what constitutes a disorder of personality. Partly for this reason the diagnosis of personality disorder remains one of the most contentious psychiatric diagnoses. Personality disorder refers to certain individual characteristics that are inflexible and result in some form of functional impairment or subjective distress for the individual. So, if this is personality disorder, what is paranoid personality disorder?

Defining Paranoid Personality Disorder

Paranoid personality disorder (PPD) is one of ten personality disorders. This disorder clusters around suspicious, odd or eccentric behaviors. The person with paranoid personality disorder, expects to be mistreated by others, is suspicious, secretive, jealous, and frequently argumentative. They have great difficulty accepting blame and appear aloof, cold and unemotional.

Diagnosing Paranoid Personality Disorder

A diagnosis of PPD assumes at least four of the following features:

  • The individual suspects, without sufficient basis, that others are exploiting, harming, or deceiving him/her.
  • Is preoccupied with unjustified doubts about the loyalty or trustworthiness of friends or associates.
  • Is reluctant to confide in others because of unwarranted fear that the information will be used maliciously against him/her.
  • Reads hidden meaning or threatening meanings into benign remarks or events and persistently bears grudges, i.e., is unforgiving of insults, injuries or slights.
  • Perceives attacks on his or her character or reputation that are not apparent to others and is quick to react angrily or to counterattack.
  • Has recurrent suspicions, without justification, regarding fidelity of spouse or sexual partner.

These features must not appear during the course of schizophrenia or other mood disorders, nor must they be related to the effects of a general medical condition or other physiological effects.

How Common is Paranoid Personality Disorder?

As with many other personality disorders people with PPD usually function well enough to hold down a job and get by. People with PPD rarely seek help from a doctor and so it is difficult to establish the full extent of the problem. Estimates vary but between 0.5% - 2.5% of the general population is thought to experience PPD, with more males than females affected.

Causes of Paranoid Personality Disorder

Various suggestions have been put forward as to what causes PPD but no one actually knows the answer. The incidence of PPD seems higher in families where one or more members have some form of psychosis such as schizophrenia. PPD may also be an aspect of learned behavior in which children learn to cope with stressful situations such as parental aggression by monitoring situations and behaviors with a higher than normal degree of vigilance. This pattern of behavior may then extend into adulthood.

Behavioral Characteristics

The person with PPD may often be told they are far too suspicious of the motives of others. They tend to be highly sensitive to rejection, hold grudges and interpret casual comments or throw-away remarks as a personal attack. Even in the face of evidence to the contrary, the person finds it hard to shake off their suspicions. Friendly everyday gestures, such as a smile, a wave, or offering the person a coffee, can be interpreted as a form of manipulation.

Getting on with someone with PPD can be hard work. They are defensive and quick to interpret situations, comments or suggestions as to how they may be put to some disadvantage. They may go as far as taking legal action against people or organizations they feel are against them and in some instances they may turn to violence.


What is paranoid personality disorder? The answer is based around a certain level of subjectivity relating to observed behavior. As to the cause of the disorder the picture is less certain. Either in isolation or combination we can point to genetics, upbringing or biochemical imbalance in the brain. PPD isn’t easy for the person who lives with it, or for those who live or interact with them. The situation however is worsened by alcohol, stress, debt, anxiety, depression or other mental health problems.


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Personality Disorders. Royal College of Psychiatrists. https://www.rcpsych.ac.uk/mentalhealthinformation/mentalhealthproblems/personalitydisorders/pd.aspx?

Satterfield JM, Feldman MD. Paranoid personality disorder. In: Ferri FF, ed. Ferri’s Clinical Advisor 2008: Instant Diagnosis and Treatment. 1st ed. Philadelphia, Pa: Mosby Elsevier; 2008.

Tyrer, P. et al. (2007) Critical developments in the assessment of personality disorder. British Journal of Psychiatry, 190 (suppl. 49), s51-s59.