There is considerable evidence for changes in brain function in association with child abuse and neglect. The fact that many of these changes are related to aspects of the stress response is not surprising. The neurobiological findings shed some light on the many emotional and behavioural difficulties which children who have been abused and neglected show. Hyperarousal, aggressive responses, dissociative reactions, difficulties with aspects of executive functions, and educational underachievement thus begin to be better understood.
The findings from neurobiological studies of brain development dealing with experience-expectant periods lead to an assumption of a deficit model, in which the lack of input to the developing child at certain critical stages of development will result in delay or absence of development of certain skills. It is therefore interesting to note that empirical findings about the effects of deprivation point to stress responses as much as to deficits.
The neurobiological findings go some considerable way towards explaining the emotional, psychological, and behavioural difficulties which are observed in abused and neglected children. The stress response offers one explanatory model for the neurobiological findings. This is particularly so for abuse that is traumatic. However, in
other instances it is not yet clear how, or to what extent, child abuse and neglect bring about the neurobiological changes. Some of the explanations may lie with experience-dependent brain development, in which the nature of early experiences shape neural connections in the maturing brain. The chronic nature of much emotional abuse and neglect negates the potential for development and change afforded by neural plasticity.
Changes in the family's social context and in the child's immediate care-giving relationships, as well the child's own adjustment, all influence the later outcome for the child's development.
Findings from the Rochester Longitudinal Study, summarised by Sameroff (1998), paint a picture of the outcome for children growing up in families of low socioeconomic status. The study identified 10 risk factors that were believed to impinge adversely on the children's development.
Four of these risk factors could be regarded as aspects of emotional abuse and neglect. No single risk factor, but increasingly in combination of 2 or more, the 10 risk factors were found to correlate with poor outcome for the children at ages 4, 13, and 18 years, on measures of cognitive, social, and emotional competence. There was very strong continuity in the existence of the risk factors over the period of the study. Composite measures of the children's mental health and competence respectively at 1, 4, and 13 years of age did not protect or predict the child's ultimate competence and mental health independently of the risk factors identified. The disadvantaged and disadvantaging environment therefore proved more powerful than the emotional health and personality of the child at every age.
Since brain development is integrally related to environmental factors, active early intervention (e.g. Zeanah & Larrieu, 1998) offers the greatest hope for children's future. The evidence on the protective effects of secure attachment in the face of stress clearly indicates a target for concern and treatment.
In support of family preservation, there is a tendency to continue to attempt to bring about changes in parent-child interaction. When these are ultimately declared ineffective, adoption is contemplated. Although for the most vulnerable children, adoption offers an alternative avenue, the good prognosis for successful outcome is inversely related to the age of the child at adoption (D. Howe, 1998). Preclinical studies with rats support this finding (Barbazanges et al., 1996).
However, the most exciting challenge for the future is to find new ways of utilising the rich evidence about the relationships between child abuse and the brain in ways that will benefit children.