Taxometric analyses of paranoid and schizoid personality disorders

There remains debate about whether personality disorders (PDs) are better conceptualized as categorical, reflecting discontinuity from normal personality; or dimensional, existing on a continuum of severity with normal personality traits. Evidence suggests that most PDs are dimensional but there is a lack of consensus about the structure of Cluster A disorders. Taxometric methods are adaptable to investigating the taxonic status of psychiatric disorders. The current study investigated the latent structure of paranoid and schizoid PDs in an epidemiological sample (N = 43,093) drawn from the National Epidemiological Survey on Alcohol and Related Conditions (NESARC) using taxometric analyses. The current study used taxometric methods to analyze three indicators of paranoid PD — mistrust, resentment, and functional disturbance — and three indicators of schizoid PD — emotional detachment, social withdrawal, and functional disturbance — derived factor analytically. Overall, taxometrics supported a dimensional rather than taxonic structure for paranoid and schizoid PDs through examination of taxometric graphs and comparative curve fit indices. Dimensional models of paranoid and schizoid PDs better predicted social functioning, role-emotional, and mental health scales in the survey than categorical models. Evidence from the current study supports recent efforts to represent paranoid and schizoid PDs as well as other PDs along broad personality dimensions.