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Infant Responses to Maternal Carrying in Human as Early Biomarker and Prognosis Estimator of Child Psychopathology: a Study on Autism Spectrum Disorders and Perinatal Brain Disorders in Early Infancy

Final Report Summary - CARRYING (Infant Responses to Maternal Carrying in Human as Early Biomarker and Prognosis Estimator of Child Psychopathology: a Study on Autism Spectrum Disorders and Perinatal Brain Disorders in Early Infancy)

In this project we aimed to understand the psycho-physiological aspects of mother-infant interaction and their paramount influence on typical and atypical development. Mother-infant bonding is the earliest and most critical social relationship of mammalian infants. To promote this bond, infants have innate behaviors to seek maternal proximity and protest upon separation via communication with the mother vocally and through body movement. However, the physiological mechanisms regulating these infant behaviors remain largely undefined. As a model to study very early mother infant interaction we studied the maternal and filial contribution during maternal carrying. In a pioneering study (Esposito et al., 2013) we have shown in rodent pups and human infants a specific calming response to maternal carrying. This calming response is a coordinated set of central, motor, and cardiac regulations and is a conserved component of mammalian mother-infant interactions. Here we aimed (i) to assess how the calming response to maternal carrying influence the efficiency of typical and adaptive mother-infant interaction; and (ii) to investigate how an adaptive maternal carrying is hindered within atypical mother-infant dyads, since the atypical characteristics may hinder the smooth development of an adaptive mother-infant interaction. We started considering mother-infant interactions within infants’ atypical development, such as Autism Spectrum Disorders and cerebral palsy, however we soon discovered that the available information about these developmental disorders were not enough to have a stable background to start from in order to interpret our TR data. After detailed analysis of videos taken during early infancy of children with developmental disabilities and discussion with several experts in the field, we decided to focus more on children with intact Central Nervous System. However, since the project aimed to study the calming responses in atypical context, we focused on what would happen in the situation where the caregiver has some special clinical condition. For this reason we investigated the role of post-partum depression that represents a relatively common condition in mothers, affecting typically 10-15% in high-income countries but up to 50% of mothers in low- and middle-income countries (~52million people worldwide yearly), and it has been associated with altered parent-infant interactions. This negative impact is both at the level of the quality of life of the people involved (social costs) and also at the level of medical treatments for the community (economical costs).

Achieved Goals
The second step of the project aimed investigated the influence of atypical characteristics within mother-infant dyads on the development of an adaptive maternal response to infants. For this part of the project we analyzed data collected at NIH (USA). Between 4 and 20 weeks postpartum, mothers completed the Beck Depression Inventory (BDI-II; Beck, Steer, & Brown, 1996). Of mothers with high BDI scores, 30 were diagnosed as having had major or minor depression within the then lifetime of the child and were included into the depressed group. Of mothers with low-BDI scores, mothers not diagnosed with any depressive disorder were selected into the non-depressed group. Thus, 30 clinically depressed (70% male infants, 53.3% firstborns) and 30 non-depressed mothers (67.7% male infants, 60% firstborns) provided data. Infants and mothers were visited in their home, and mothers were asked to behave as they normally would and to ignore the presence of the researcher. Infants and mothers were audio/video recorded continuously for a minimum of 50 min. Maternal behaviors during infant cry were then coded and analyzed. Analysis revealed that non-depressed mothers fed, rocked, and touched their infants for relatively more time than clinically depressed mothers. Clinically depressed mothers were non interactive for relatively more time than non-depressed mothers. Furthermore, during infant cry non-depressed were overall more active than clinically depressed mothers. Also, applying predictive models (tree based models) it emerged that the clinical diagnosis of the mother was the best predictor of maternal behaviors during their infant’s crying. Clinically depressed mothers engaged in less caregiving overall during their infants’ crying. In this last period all these findings, as well as the ones collected during the first period, have been successfully disseminated within both scientific community and broader public as well as within young people through publications in peer-reviewed journals, newspaper press release, summer schools, websites, workshops and seminars.