Genetic and Environmental Risk Factors for DSM-5 Section II Personality Disorders and Section III Pathological Personality Traits

Background. The classification of personality disorders (PDs) in DSM-5 Section II includes 10 categorical PDs. The Alternative Model (Section III) includes criteria for dimensional measures of pathological personality traits... [ view full abstract ]

Background. The classification of personality disorders (PDs) in DSM-5 Section II includes 10 categorical PDs. The Alternative Model (Section III) includes criteria for dimensional measures of pathological personality traits organized into five domains. The degree to which genetic and environmental influences on the two conceptualizations are shared is not known.

Methods. We used data from a large longitudinal population-based study of young adult Norwegian twins. DSM-IV PDs were assessed using structured interviews.  The five domains of the DSM-5 Alternative Model plus a domain explicitly targeting compulsivity were measured by a short self-report inventory. Schizotypal, Paranoid, Antisocial, Borderline, Avoidant and Obsessive-compulsive PDs were assessed at the same time as the pathological personality traits and 10 years previously. Schizoid, Histrionic, Narcissistic, and Dependent PDs were only assessed at the first interview. Biometric models were used to estimate overlap in genetic and environmental risk factors.

Results. Genetic correlations between the individual domains and PDs ranged from + 0.21 to + 0.91. When measured concurrently, there was 100% overlap between genetic risk factors for the pathological trait domains in aggregate and for Paranoid, Schizotypal, Antisocial, Borderline and Avoidant PDs respectively.

Conclusion. The pathological personality trait domains of the Alternative Model for classification of PDs in DSM-5 section III, appears to tap, at an aggregate level, the same genetic risk factors as the DSM-5 section II classification for most of the PDs.