Latent Class Analysis of DSM-IV Schizotypal Personality Disorder Criteria in Psychiatric Patients

The aim of the study was to evaluate the latent structure of DSM-IV schizotypal personality disorder (SPD) diagnostic criteria. The sample consisted of 564 consecutively admitted inpatients and outpatients. Exploratory latent class analysis identified a four-class model as the best fitting model for DSM-IV SPD criteria. The first of the SPD latent classes was mainly characterized by odd thinking, inappropriate affect, and interpersonal features; the second class by cognitive/perceptual difficulties; the third class by paranoid features; and the fourth class by absence of SPD features. The conditional probability pattern of the four-class solution could be safely replicated across confounder strata. Unlike previous findings, oddness, aloofness, and social withdrawal, rather than positive symptoms, best characterized SPD even in clinical samples.