Schizotypal personality disorder (STPD) or schizotypal disorder is a mental disorder characterized by severe social anxiety, paranoia, and often unconventional beliefs. People with this disorder feel extreme discomfort with maintaining close relationships with people, mainly for the fact that they think that their peers harbor negative thoughts towards them, so they avoid forming them. Peculiar speech mannerisms and odd modes of dress are also diagnostic signs of this disorder. In some cases, people with STPD may react oddly in conversations, not respond, or talk to themselves.