Definition of Paranoid personality disorder:

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

Causes, incidence, and risk factors:

The causes of paranoid personality disorder are unknown. The disorder appears to be more common in families with psychotic disorders such as schizophrenia and delusional disorder, which suggests genes may be involved. However, environmental factors may play a role, as well.

The condition appears to be more common in men.

Symptoms:

People with paranoid personality disorder are highly suspicious of other people. As a result, people with this condition severely limit their social lives.

They often feel that they are in danger, and look for evidence to support their suspicions. People with this disorder 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 by others
• Inability to work together with others
• Social isolation
• Detachment
• Hostility

Signs and tests:

Like other personality disorders, paranoid personality disorder is diagnosed based on a psychological evaluation and the history and severity of the symptoms.

Treatment:

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.

Expectations (prognosis):

The outlook usually depends on whether the person is willing to accept help. Therapy and medications can reduce paranoia and limit its impact on the person's daily functioning.

Complications:

• Extreme social isolation
• Interference with work

Calling your health care provider:

If suspicions are interfering with your relationships or work, contact a health care provider or mental health professional.