Schizotypal personality disorder is a mental health condition in which a person has trouble with relationships and disturbances in thought patterns, appearance, and behavior.

Cause of schizotypal personality disorder is unknown. Genes are thought to be involved because this condition is more common in relatives of schizophrenics.

Schizotypal personality disorder should not be confused with schizophrenia. People with schizotypal personality disorder can have odd beliefs and behaviors. But unlike people with schizophrenia, they are not disconnected from reality and usually do not hallucinate. They also do not have delusions.

People with schizotypal personality disorder may be very disturbed. For example, they may also have unusual preoccupations and fears, such as fear of being monitored by government agencies.

More commonly, people with this disorder behave oddly and have unusual beliefs (such as aliens). They cling to these beliefs so strongly that they have difficulty forming and keeping close relationships.

People with this disorder may also have depression. A second personality disorder, such as paranoid personality disorder, is also common.

Common signs of schizotypal personality disorder include:

• Discomfort in social situations
• Inappropriate displays of feelings
• No close friends
• Odd behavior or appearance
• Odd beliefs, fantasies, or preoccupations
• Odd speech

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

Talk therapy is an important part of treatment. Social skills training can help some people cope with social situations. Medicines may also be a helpful addition.

Schizotypal personality disorder is usually a long-term (chronic) illness. Outcome of treatment varies based on the severity of the disorder.

• Poor social skills
• Lack of interpersonal relationships

See your health care provider or a mental health professional if you or someone you know has symptoms of schizotypal personality disorder.

There is no known prevention. Awareness of risk, such as a family history of schizophrenia, may allow early diagnosis.

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 Mosby; 2008:chap 39.