Is antisocial personality disorder continuous or categorical? A taxometric analysis

Although the DSM-IV-TR is organized into discrete disorders, the question of whether a given disorder possesses a dimensional or a categorical latent structure is an empirical one that can be examined using taxometric methods. The objective of this study was to ascertain the latent structure of antisocial personality disorder (ASPD).

Participants were 1146 male offenders incarcerated in state prisons (n=569), or court-ordered to residential drug treatment (n=577). Participants were interviewed using the Structured Clinical Interview for DSM-IV Axis II Personality Disorders (SCID-II) to assess ASPD symptoms; they also completed the Personality Diagnostic Questionnaire-4 (PDQ-4) ASPD scale. Taxometric analyses were performed to examine whether ASPD is underpinned by a discrete category or a dimensional construct.

Multiple taxometric procedures using two different sets of indicators provided no evidence that ASPD has a taxonic latent structure. Instead, the results were far more consistent with the proposition that ASPD exists on a continuum, regardless of whether it is assessed using a structured interview or a self-report measure.

Evidence that ASPD is dimensional suggests that it is best studied using continuous measures and that dichotomizing individuals into ASPD versus non-ASPD groups will typically result in decreased statistical power. The findings are also consistent with a multifactorial etiology for ASPD and with recent attempts to conceptualize ASPD within the framework of extant dimensional models of personality.