Bipolar-Risk Allele Associated With Higher Openness to Experience
The diacylglycerol kinase η gene is one of the few replicated genes that increases the risk for bipolar disorder.
People with the diacylglycerol kinase η gene (DGKH), a bipolar-risk allele, score higher on measures of openness to experience than those without the gene, according to results published in Journal of the Affective Disorders.
Openness to experience has been suggested as a premorbid personality trait for bipolar disorder, so these results provide further evidence that DGKH plays a role in the etiology of the disorder.
The study included 319 healthy participants. The researchers assessed personality by the NEO Personality Inventory-Revised, which includes neuroticism, extraversion, openness to experience, agreeableness, and consciousness dimensions. Investigators used a polymerase chain reaction-restriction fragment length polymorphism method to detect the A/G polymorphism of DGKH (rs9525580). Participants were divided into 2 groups based on the presence or absence of the A allele, which is a putative risk allele for bipolar disorder.
Participants who had the A allele had significantly higher scores for openness to experience compared with participants who did not have the allele (P <.05). The scores for other personality dimensions did not differ significantly between the 2 groups.
The researchers noted that their study had 2 significant limitations. The participants in the study had a homogenous but specific background — they were all young and well-educated people from Japan. They also noted they did not employ a longitudinal design, so it is not clear whether bipolar disorder developed in the participants with high openness.
Investigators wrote, “the present study provides further evidence for the implication of DGKH in the etiology of bipolar disorder.”
Matsumoto Y, Suzuki A, Shirata T, et al. Implication of the DGKH genotype in openness to experience, a premorbid personality trait of bipolar disorder. J Affect Disord. 2018;238:539-541.