Correlation of serotonin transporter gene polymorphism with temperament in Persian medicine

Background: Despite its effectiveness, there are still many concerns and questions about the principles and therapeutic methods of traditional medicine (TM). In other words, in order to accept TM as a reliable health care system, its proficiency need to be declared through modern scientific research. One of the major determinants of Persian medicine (PM) which is practically utilized in diseases diagnosis and cure is temperament. Considering the association of depression with the coldness of temperament as well as with the 5-HTTLPR polymorphism, we proposed that the serotonin transporter gene could be a candidate gene contributing to the variation of temperament. To test this hypothesis, in this study, we examined the association of 5HTTLPR polymorphism with the hot/cold status of temperament in the healthy individuals. Materials and Methods: The study included 352 healthy men (aged between 20-40 years) referred to the organization of blood transfusion, located in Shiraz city, southern Iran. The participants’ hot/cold status of temperament (warm, temperate and cold) was determined using a standard self-reported scale and to genotype the 5HTTLPR polymorphism, polymerase chain reaction (PCR) was performed. Multinomial logistic regression was used to evaluate 95% CI and ORs for the association of temperament with the 5HTTLPR genotypes. Statistical analysis was performed using the SPSS software with P<0.05 significance level. Results: In the term of warm temperament, no association with the 5HTTLPR genotypes was observed. However, in respect of cold temperament, our data showed no association with the SS, but the LS genotype; that is, with the reference to the LL, the LS genotype decreased the possibility of coldness rather than temperateness for the temperament (OR=0.471, p=0.040). Conclusion: Our data revealed the association of temperament with the 5HTTLPR polymorphism which suggest that the temperament may be influenced by the serotonergic system. Further surveys are required to more declare the relation of genetic factors with the temperament.