Influence of trauma exposure or early life stress and Serotonin Transporter (5-HTTLPR) Genotype on subjective- and physiological stress reactivity in healthy male subjects

Abstract

Background: This study investigated whether 5-HTTLPR variation and childhood trauma or early adverse life events independently and interactively predict psychological- and physiological stress responses in healthy adult male subjects. Methods: All men were between 18 and 29 years old, mentally and physically healthy and without current or lifetime psychopathology. Of the 79 subjects participating in this study, 40 subjects were allocated to the stress condition, 39 to the control condition. The Trier Social Stress Test for Groups (TSST-G) was used for the induction of psychosocial stress in group format. The polymorphism 5-HTTLPR variation was obtained from blood samples, using two tagging single-nucleotide polymorphisms (SNPs; rs2129785 and rs11867581). The JTV and LSC-R were used to examine childhood trauma and previous life events. Stress reactivity was assessed as (1) subjective assessment with visual analogue scales for stress, anxiety and uncertainty over two minute time points during and before the TSST-G and (2) averaged heart rate over two ten minutes time periods during and before the TSST-G. Results: The stress condition showed stronger subjective stress reactivity and heart reactivity than the control condition due to the TSST-G, suggesting a good efficacy of the TSST-G stress protocol. No independent- or interactive effects were found for the 5-HTTLPR polymorphism and childhood trauma or previous stress exposure on psychological- and physiological stress reactivity. Conclusion: The 5-HTTLPR polymorphism S allele and exposure to childhood trauma or previous life events seemed to be unrelated to changes in subjective stress reactivity and heart rate reactivity in healthy men who were free of psychopathology. The current findings do not confirm the suggested role of a gene- environment interaction to stress reactivity and further verification with a larger sample size and longitudinal evaluation is required.