In community studies of schizotypal personality disorder, reported rates range from 0.6% in Norwegian samples to 4.6% in a U.S. community sample. The prevalence of schizotypal personality disorder in clinical populations seems to be infrequent (0%-1.9%), with a higher estimated prevalence in the general population (3.9%) found in the National Epi demiologic Survey on Alcohol and Related Conditions.