Genetics of Personality Disorders

Abstract

Evidence from family, adoption and twin studies indicates that genetic factors significantly influence liability to personality disorders (PDs) and contribute to the comorbidity among PDs and between PDs and other psychiatric disorders. Molecular genetic studies aimed at identifying specific genes have been applied, to a limited extent, to personality. Significant associations have, however, been found with candidate genes related to neurotransmitter pathways, especially in the dopaminergic or serotonergic systems. Both quantitative and molecular genetic studies indicate that gene–environment correlation and interaction play a role in the aetiology of PDs. Methods like genome‐wide association studies, analyses of copy‐number variation, studies of rare genetic variants and epigenetic methods are only recently being applied to PDs, but will hopefully contribute to our future understanding of the causal mechanisms involved. Key Concepts Personality disorders are categorical concepts in the Diagnostic and Statistical Manual of Mental Disorders, but an emerging model conceptualises personality pathology along 5 domains that subsume 25 lower order facets. Personality disorders are significantly influenced by genetic factors. Comorbidity between personality disorders and between personality disorders and other mental disorders are significantly influenced by shared genetic liability. Candidate gene association studies indicate significant relationships between personality disorders and genes related to neurotransmitter pathways, especially in the dopaminergic or serotonergic systems. Both quantitative and molecular genetic studies suggest that gene–environment interplay is involved in the aetiology of personality disorders.