Schizotypal personality disorder (STPD), also known as schizotypal disorder, is a mental and behavioural disorder. DSM classification describes the disorder specifically as a personality disorder characterized by thought disorder, paranoia, a characteristic form of social anxiety, derealization, transient psychosis, and unconventional beliefs. People with this disorder feel pronounced discomfort in forming and maintaining social connections with other people, primarily due to the belief that other people harbour negative thoughts and views about them. Peculiar speech mannerisms and socially unexpected modes of dress are also characteristic. Schizotypal people may react oddly in conversations, not respond, or talk to themselves. They frequently interpret situations as being strange or having unusual meaning for them; paranormal and superstitious beliefs are common. Schizotypal people usually disagree with the suggestion their thoughts and behaviour are a 'disorder', and seek medical attention for depression or anxiety instead. Schizotypal personality disorder occurs in approximately 3% of the general population and is more common in males.
The term "schizotype" was first coined by Sandor Rado in 1956 as an abbreviation of "schizophrenic phenotype". STPD is classified as a cluster A personality disorder, also known as the "odd or eccentric" cluster.