Association between the serotonin transporter polymorphism (5HTTLPR) and subjective happiness level in Japanese adults

摘要

Background An epidemiological study in the USA recently reported that variations in the serotonin transporter gene-linked polymorphic region (5HTTLPR) can influence subjective well-being or happiness; specifically, individuals with long polymorphisms (L-allele carriers), associated with increased serotonin reuptake activity, reported significantly higher levels of life satisfaction compared to individuals with short polymorphisms (S-allele carriers). It is empirically known that an international discrepancy in subjective well-being exists, which may be linked to findings that the genotype distribution is different in the USA and Japan. Thus, we investigated the association between 5HTTLPR and happiness in Japan to examine whether geographical heterogeneity of well-being could be partly explained by variations in 5HTTLPR. Findings Ninety-two healthy Japanese individuals were recruited (34 males and 58 females; age range, 19-40 years). Subjective happiness was evaluated using the Japanese version of the Subjective Happiness Scale. Regression analysis examining the association between 5HTTLPR and subjective happiness level revealed that L-allele carriers report a significantly higher level of subjective happiness. Conclusions In concurrence with the epidemiological findings of the USA, this study indicates that 5HTTLPR is associated with subjective happiness levels in Japanese adults. In turn, this might provide some insight into the potential mechanism underlying international differences in subjective well-being or happiness.