5-HT2A SNPs and the Temperament and Character Inventory

Temperamental traits, the most basic part of personality, have been largely correlated with neurotransmitter systems and are under genetic control. Among serotonin candidates, the 2A receptor (5-HT_2A) received considerable attention. We analyzed four SNPs (rs643627, rs594242, rs6311 and rs6313) in the 5-HT_2A gene and their association with personality traits, as measured with the Temperament and Character Inventory (TCI). The sample was composed of three sub-groups: two German sub-samples, consisting of a healthy group of 289 subjects (42.6% males, mean age: 45.2 ± 14.9) and a psychiatric patient group of 111 suicide attempters (38.7% males, mean age: 39.2 ± 13.6), and an Italian sub-sample, composed of 60 mood disorder patients (35.0% males, mean age: 44.0 ± 14.8). Controlling for sex, age and educational level, the SNPs were not strongly associated with personality dimensions. Only the rs594242 showed an association with Self-Directedness (p = 0.003) in the German sample, while rs6313 was marginally associated with Novelty Seeking (p = 0.01) in the Italian sample. We conclude that 5-HT_2A SNPs may marginally modulate personality traits but further studies are required.