Paranoid personality disorder is a mental health condition in which a person has a long-term pattern of distrust and suspicion of others, but does not have a full-blown psychotic disorder such as schizophrenia.

Personality disorder - paranoid

Cause of paranoid personality disorder is unknown. The disorder appears to be more common in families with psychotic disorders such as schizophrenia and delusional disorder. This suggests genes may be involved. Environmental factors may play a role as well.

The condition appears to be more common in men.

Persons with paranoid personality disorder are very suspicious of other people. As a result, they severely limit their social lives. They often feel that they are in danger and look for evidence to support their suspicions. They have trouble seeing that their distrustfulness is out of proportion to their environment.

Common symptoms include:

• Concern that other people have hidden motives
• Expectation that they will be exploited (used) by others
• Inability to work together with others
• Social isolation
• Detachment
• Hostility

Paranoid personality disorder is diagnosed based on a psychological evaluation that assesses the history and severity of the symptoms.

Treatment is difficult because people with this condition are often very suspicious of doctors. If treatment is accepted, talk therapy and medications can often be effective.

Outlook usually depends on whether the person is willing to accept help. Talk therapy and medications can sometimes reduce paranoia and limit its impact on the person's daily functioning.

• Extreme social isolation
• Problems with school or work

See a health care provider or mental health professional if suspicions are interfering with your relationships or work.

Blais MA, Smallwood P, Groves JE, Rivas-Vazquez RA. Personality and personality disorders. In: Stern TA, Rosenbaum JF, Fava M, Biederman J, Rauch SL, eds. Massachusetts General Hospital Comprehensive Clinical Psychiatry. 1st ed. Philadelphia, PA: Elsevier Elsevier; 2008:chap 39.