The structure of DSM-III-R schizotypal personality disorder diagnosed by direct interviews

Confirmatory factor analysis techniques were applied to test how competing models (unifactorial, bifactorial, and trifactorial) could be used to explain the structure of schizotypal disorder as defined in DSM-III-R and DSM-IV. Subjects were 538 nonpsychotic psychiatric outpatients and a replication sample of 225 nonpsychiatric patients and control subjects, interviewed by clinicians using the Structured Interview for DSM-III-R Personality Disorders. The study found that the best-fit solution encompassed three factors: cognitive-perceptual, interpersonal, and oddness. Future studies may benefit from considering schizotypal personality disorder as composed of three factors that may indicate the existence of three underlying (dys)functional systems.