Dynamic interactions between genes and environment during early life experiences can result in different psychobiological pathways in adulthood. Evidences from animal studies showed a direct link between the maternal care environment and long-term effects on neural systems. Such neurobiological effects seem to be, partially, mediated by epigenetic changes that allow to alter the activity of some genes, without modifying the inherited nucleotide sequences. General purpose of this project is to investigate whether early interactions between the parents and their infant are correlated with epigenetic changes in a specific set of genes. The aim is to test whether, since birth, a low degree of reciprocity in the interaction between caregiver and newborn and the resulting attachment style are associated with a specific epigenetic expression pattern of a pool of candidate genes related to major developmental psychopathologies.
50 newborns with both their own parents will be enrolled at the Obstetric Unit of the Santo Spirito in Sassia Hospital, Rome. The study will involve 4 different time-frames: Time 0, before the childbirth; Time 1, 48 hours after the childbirth; Time 2, at the first month; Time 3, at third month. At Time 0, the informed consent will be collected, and the prenatal attachment toward the fetus of both parents will be evaluated. At each time frame, psychological dimensions of the parents and the interaction between parents and newborn will be audio-video recorded in order to subsequently codify the quality of the interactions. Moreover, at each assessment sessions a biological sample (saliva) will be collected both from parents and the newborn using a buccal swab, in order to analyze DNA methylation mechanisms of a pool of candidate genes. To the best of our knowledge, this study is the first to investigate, in systematic way, the importance of the relational and psychological variables on the epigenome in humans.
Expected outcomes
The main expected result is an association between a poor reciprocity and contingency of the interaction between parents and infant and a reduction of the expression of DAT and SERT. Thus, we expect that the interaction between parent and infant will predict the epigenetic modifications of the candidate genes.
Another expected result is an association between a better reciprocity and contingency of the interaction assessed at Time 1, Time 2 and Time 3, a higher number of episodes of parent-newborn contact assessed using the diary. Moreover, we expect that higher levels of postpartum depression and alexithymia will be associated with less reciprocity and contingency in the mother-newborn interaction.
Finally, we expect that parent attachment style will predict the pattern of interaction between parent and newborn.
This project could allow massively further the comprehension of the complex interaction between environmental and genetic factors. The current point of view is that some psychopathologies, such as schizophrenia and autism, are strongly due to genetic inheritance. This point of view, which appears extremely reductionist, is not able to explain the complexity of emotional psychopathologies and does not allow to bring consistent evidences about them. On the other hand, the emerging data from epigenetic studies suggest how much the environment can affect the expression of the genes, independently from the inherited DNA. This alteration of the gene levels expression correlates with a poor mental health.
Building from recent findings in animal models, it could be conceivable that in humans there are shared and similar epigenetic mechanisms that change the levels of expression of specific genes. To the best of knowledge, this study is the first to investigate, in a systematic way, the importance of the relational and psychological variables on the epigenome in humans. The longitudinal design of the project could give the possibility to control the progress of possible epigenetic modifications, in correlation with the characteristics of the relational and communicative style between the parents and their infant. The opportunity to investigate the psychological variables that affect the epigenetic mechanisms could allow us to recognize really early the risk for development of psychopathologies that are unlikely to be diagnosed before the third year of life. Having the possibility to detect the environmental factors that result in epigenetic changes could allow us to intervene and treat precociously the developmental diseases, in epigenetic and psychological ways. Moreover, the systematic study of the epigenetic changes associated to the relationship between the parents and their infant could give an important contribution to the study of the first interactions with the newborn, helping to prevent the growing difficulties that affect the parents after childbirth, sometimes resulting in postpartum depression in the mothers.
This project could highlight the relevance of psychological factors in the onset of emotional and developmental diseases, that often are considered exclusively from genetic and biological perspectives, giving a new integrated and multidisciplinary approach to mental health. The integration of different scientific approaches involved in this project is a great point of strength because it could allow to deepen the understanding of the etiology of psychopathologies from a more exhaustive point of view. The multidisciplinary character of this project could make it possible to develop new and broad-based measurements and models, using the specific techniques and knowledge of each discipline.