While studies have examined risk factors and consequences of child maltreatment in general, relatively few have focused specifically on neglect, especially maternally perpetrated child neglect. This is despite evidence that neglect is the most common and most rapidly increasing form of maltreatment, with some of the most serious long-term effects on child development. Maternal neglect constitutes a substantial disturbance in the mother-child relationship. For this reason, after establishing the epidemiology of neglect at a population level, this thesis examines the neurobiology of patterns of mother-infant attachment using functional MRI. Disturbance in mother-infant attachment, in conjunction with family, social and societal risk and protective factors, constitutes the likely pathway to maternal neglect. Specific objectives were: 1) to describe the magnitude of the problem of maternal neglect in Australia, using longitudinal population-based studies; 2) to identify risk and protective factors associated with neglect, both in a high risk population of extremely low birth weight (ELBW) infants and a representative birth cohort; 3) to specifically explore whether breastfeeding was protective against maternally perpetrated neglect; 4) to examine the consequences of child neglect on infant cognitive development and head growth; and 5) to determine how maternal brain and endocrine responses differ according to patterns of adult attachment security. In Part A, two cohort studies examined the epidemiology of child abuse and neglect among mothers and their infants born at the Mater Mothers’ Hospital in Brisbane, Australia. Cohort databases were confidentially linked with official notifications of child abuse and neglect. The first cohort included 353 ELBW infants who were assessed at birth and at 1, 2 and 4 years of age. The second cohort included 7223 children whose mothers were enrolled prenatally into the Mater-University of Queensland Study of Pregnancy (MUSP), where data were collected at birth, 6 months, and 5 and 14 years. The initial ELBW study examined all reported notifications of neglect, while the MUSP study focused particularly on substantiated maternally perpetrated neglect and the protective effect of breastfeeding. These studies examined a broad range of social and biological predictors. Outcome variables for child neglect were examined in the ELBW cohort using cognitive z-scores and growth parameters. Analytic techniques included multivariate modelling. In Part B, the neurobiology of mother-infant attachment was examined by monitoring a cohort of 61 first-time mothers from Houston, Texas, over 4 study visits. The mothers’ attachment classifications were determined during pregnancy using the Adult Attachment Interview. At 6 months, mother-infant pairs were videotaped, and serum oxytocin measures collected before, during and after interaction. At 10 months, the mothers viewed pictures of their own and unknown infants during functional MRI scanning. The first report examined the brain responses of 28 mothers to happy, neutral and sad infant face cues. The next compared brain responses of 15 mothers with “secure” attachment patterns to 15 “insecure/dismissing” mothers, and also examined differences in peripheral oxytocin response to mother-infant interaction. Data were analysed using a general linear model and repeated measures ANOVA. Overall, more than 1 in 10 children were reported for suspected child maltreatment, 3-5% as a result of substantiated neglect and 3% with maternally perpetrated neglect, with higher rates seen in the ELBW cohort. Duration of breastfeeding was inversely associated with the odds of maternal neglect, with non-breastfeeding mothers almost 4 times more likely to neglect their child compared to mothers who breastfed for 4 or more months, after adjusting for covariates. Other significant risk factors for substantiated maternal neglect included low education, young maternal age, and race, which were also significant univariate predictors in the ELBW population. ELBW children exposed to neglect showed a progressive decline in cognitive functioning over the first 4 years of life, as well as a significantly reduced head circumference at 2 and 4 years. When mothers viewed their own infant’s faces, compared with an unknown infant, key dopamine-associated reward processing regions of the brain were activated, including the midbrain’s ventral tegmental area/substantia nigra, striatum and prefrontal cortex. Mothers with an insecure/dismissing type of attachment showed significantly less activation of these reward regions in response to both happy and sad own-infant faces. On viewing their own infant’s crying faces, these mothers showed activation of the anterior insula, a region involved in feelings of unfairness, pain and disgust. “Secure” mothers showed greater peripheral oxytocin responses during mother-infant interaction, which were correlated with activation of the pituitary/hypothalamic region of the brain, where oxytocin is produced and secreted. These findings confirm the magnitude of neglect as a public health concern, with identifiable consequences and specific risk and protective factors. The neurobiological studies identify neuroendocrine systems associated with mother-infant responses and patterns of adult attachment. Together, these studies theoretically link secure mother-infant attachment with brain reward activation and oxytocin response, breastfeeding success, and a reduced risk for maternal neglect. Implications for prevention and intervention, and future research plans, are discussed.
| Identifer | oai:union.ndltd.org:ADTP/254278 |
| Creators | Lane Strathearn |
| Source Sets | Australiasian Digital Theses Program |
| Detected Language | English |
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