The importance of understanding which environmental and biological factors are involved in determining individual differences in physiological response to stress is widely recognized, as the impact of stress on physical and mental health cannot be ignored. Many researchers believe that our ability to cope with stress originates in infancy through the interaction between our experiences and genes. Several studies have shown how attachment relationships as well as some temperamental traits play a significant role in modulating Hypothalamic Pituitary Adrenal (HPA) axis reactivity to the stress of separation from the mother, as indexed by salivary Cortisol. However, no published studies have investigated their effects on Sympathetic Adreno Medulla (SAM) system reactivity, as indexed by salivary alpha amylase which was recently found to be a marker of SAM activity. Moreover, the contribution of genetics in predicting salivary Cortisol and alpha amylase response to stress in infants has not been investigated yet. In the present study, the child-mother attachment relationship, some genetic polymorphisms (DRD4, DRD4/521, COMT and 5-HTT), and temperamental traits were tested as predictors of both physiological markers during the Strange Situation (SS) procedure in an Italian sample of around 70 healthy infants aged 12 to 18 months. HPA and SAM activity was predicted by a larger number of gene x environment interactions in comparison with the number of separate constitutional (genes and temperament) and environmental (attachment patterns) factors. These results help to disentangle the role played by both biological 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 and associations with behaviour.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:497882 |
| Date | January 2008 |
| Creators | Frigerio, Alessandra |
| Publisher | University College London (University of London) |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://discovery.ucl.ac.uk/1445494/ |
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