Serotonin receptor gene (5-HT1A) modulates alexithymic characteristics and attachment orientation

Previous studies have indicated that alexithymia is associated with the availability of serotonin in the brain and with the insecure attachment orientation. Inspired by the finding that the receptor 5-HT1A modulates the level of serotonin in the brain, this study investigated to what extent a polymorphism (C-1019G, rs6295) of 5-HT1A gene modulates individuals' alexithymic characteristics and attachment orientation in 504 Chinese Han people. Results showed significantly higher total scores on the 20-item Toronto Alexithymia Scale (TAS-20) for individuals carrying the CG/GG genotype than for individuals carrying the CC genotype. Specifically, individuals with the CG/GG genotype reported greater difficulty in identifying own feelings than individuals with the CC genotype. Results also showed that individuals carrying the CG/GG genotype seemed to be less comfortable with having close relationships to others than individuals with the CC genotype. These findings provide the first evidence for the link between 5-HT1A and the development of alexithymic characteristics and attachment orientation.