Background: The 9-repeat variable number tandem repeat allele of the dopamine transporter has recently been associated with borderline personality disorder (BPD) in depressed patients.
Methods: We investigated the association between the 9-repeat allele of the dopamine transporter and angry-impulsive personality traits in a family study with 512 subjects on the molecular genetics of depression and personality.
Results: Across the whole sample, the 9-repeat allele of the dopamine transporter was associated with angry-impulsive personality traits (p = .002). This association was stronger in subjects with no history of mood disorders or BPD (odds ratio [OR] = 4.85, p = .008) than in subjects with a history of mood disorders (OR = 1.73, p = .033). Angry-impulsive traits were also associated with lifetime mood disorder diagnoses and with BPD.
Conclusions: The associations reported in this article suggest that the 9-repeat allele of the dopamine transporter is associated with angry-impulsive personality traits, independent of any link to mood disorder or BPD. This could form the basis of a dopaminergic neurobiological model of angry-impulsive personality traits.