Definition of Schizotypal personality disorder:

Schizotypal personality disorder is a psychiatric condition in which a person has difficulty with interpersonal relationships and disturbances in thought patterns, appearance, and behavior.

Causes, incidence, and risk factors:

The cause is unknown. Genes are thought to be involved, because there is an increased incidence of this condition in relatives of schizophrenics.

However, schizotypal personality disorder should not be confused with schizophrenia. People with schizotypal personality disorder tend to have odd beliefs and behaviors, but they are not disconnected from reality and usually do not hallucinate. Hallucinations, delusions, and complete unawareness of reality are hallmarks of untreated or unsuccessfully treated schizophrenia.

Between 30% and 50% of people with schizotypal personality disorder also have a major depressive disorder. A second personality disorder, such as paranoid personality disorder, is also common with this condition.