Eugenio Medea' Scientific Institute, Italy.
J Child Psychol Psychiatry. 2009 Dec;50(12):1513-22. doi: 10.1111/j.1469-7610.2009.02126.x. Epub 2009 Jul 22.
The importance of understanding which environmental and biological factors are involved in determining individual differences in physiological response to stress is widely recognized, given the impact that stress has on physical and mental health.
The child-mother attachment relationship and some genetic polymorphisms (5-HTTLPR, COMT and GABRA6) were tested as predictors of salivary cortisol and alpha amylase concentrations, two biomarkers of hypothalamic-pituitary-adrenocortical (HPA) axis and sympathetic adrenomedullary (SAM) system activity, during the Strange Situation (SS) procedure in a sample of more than 100 healthy infants, aged 12 to 18 months.
Individual differences in alpha amylase response to separation were predicted by security of attachment in interaction with 5-HTTLPR and GABRA6 genetic polymorphisms, whereas alpha amylase basal levels were predicted by COMT x attachment interaction. No significant effect of attachment, genetics and their interaction on cortisol activity emerged.
These results help to disentangle the role played by both genetic and environmental factors in determining individual differences in stress response in infancy. The results also shed light on the suggestion that HPA and SAM systems are likely to have different characteristic responses to stress.
鉴于压力对身心健康的影响，人们广泛认识到理解哪些环境和生物因素参与决定个体对应激的生理反应差异的重要性。
在一个超过 100 名 12 至 18 个月大的健康婴儿的样本中，通过陌生人情境（SS）程序，我们将儿童-母亲依恋关系和一些遗传多态性（5-HTTLPR、COMT 和 GABRA6）作为唾液皮质醇和 alpha 淀粉酶浓度的预测因子进行测试，这两种生物标志物可以反映下丘脑-垂体-肾上腺皮质（HPA）轴和交感肾上腺髓质（SAM）系统的活动。
与 5-HTTLPR 和 GABRA6 遗传多态性相互作用的依恋安全性预测了分离时 alpha 淀粉酶反应的个体差异，而 COMTx 依恋相互作用则预测了 alpha 淀粉酶的基础水平。依恋、遗传学及其相互作用对皮质醇活性没有显著影响。
这些结果有助于阐明遗传和环境因素在决定婴儿期应激反应个体差异中的作用。研究结果还表明，HPA 和 SAM 系统可能对压力有不同的特征反应。
