Schizotypal personality disorder is characterized by a long history of troubled relationships and disturbances in thought patterns, appearance and behavior. While the cause is unknown, it is most common in family members of schizophrenics. People with this disorder may also have depression and a second personality disorder, such as paranoid personality disorder. Individuals with schizotypal personality disorder are known to behave oddly and have unusual beliefs (like a fear of being monitored by government agencies or a belief in aliens) and these actions and thoughts prevent the forming of close relationships. Talk therapy is the cornerstone of treatment and medication may also be prescribed.