Serotonin transporter gene (SLC6A4) variation and sensory processing sensitivity—Comparison with other anxiety-related temperamental dimensions

Background: The short (s) allele of the 5-HTTLPR polymorphism in the promoter region of the human serotonin transporter (5-HTT) gene SLC6A4 has previously been associated with anxiety-related personality dimensions. However, this relationship has not been confirmed in all studies and may be modified by environmental circumstances and/or psychiatric illness. This study examined whether the temperamental trait sensory processing sensitivity (SPS), characterized by increased responsivity to environmental stimuli, is related to 5-HTTLPR/rs25531 genotype. Methods: 5-HTTLPR and rs25531 genotypes, level of SPS, self-reported Revised NEO Personality Inventory (NEO-PI-R) and Temperament and Character Inventory (TCI) personality profiles, and symptoms of psychological distress (SCL-90R Global Severity Index) were determined for 405 healthy volunteers. Results: Sensory processing sensitivity was highly correlated with the anxiety-related dimensions of the NEO-PI-R and the TCI models of personality, Neuroticism, and Harm Avoidance, respectively. However, the level of SPS was not associated with the combined 5-HTTLPR and rs25531 s′/s′ genotype. Neuroticism and Harm Avoidance were also not associated with 5-HTTLPR/rs25531 s′/s′ genotype. Correcting for symptoms of psychological distress had no effect on the relationships between personality and genotype. Conclusion: The level of SPS was not associated with serotonin transporter gene variation. Further, combined 5-HTTLPR and rs25531 genotype was not associated with other anxiety-related dimensions.