Prevention of child maltreatment: strategic targeting of a curvilinear relationship between adversity and psychiatric impairment
Authors: John N. Constantino
Journal: World Psychiatry (2018)

Child maltreatment – which includes physical, emotional and sexual abuse as well as neglect – is the single most influential known cause of lifetime mental health impairment that is preventable (the other high-impact causes being primarily genetic), with conservative estimates of prevalence of about 15% in high-income countries1, 2. Its deleterious impact arguably accounts for 25% or more of the population-attributable risk for child psychopathology1, 3, and in severe cases can extend to the lack of the minimum requirements for normative human development (food, hygiene, human interaction), physical injury, sexual exploitation and mutilation, permanent brain injury and death4, or be associated with perpetration of child abuse by victims when they reach adulthood5. Maltreatment most commonly first occurs in infancy, particularly when adult caregivers are too stressed or functionally incapacitated to attend to the needs of the children under their care. The long-term cost for each yearly cohort of children abused in the US alone has been conservatively estimated to exceed $124 billions6. Our ability to predict child maltreatment on the basis of risk indicators that can be feasibly ascertained on the first day of an infant's life (including indices of parental mental health or substance use impairment, concentrated poverty, and a range of socio-economic stress indicators) has considerably advanced7, and specific risk profiles can be delineated identifying a subgroup of children who have an up to 70% likelihood of ultimately being detected in official governmental records for child abuse/neglect. In spite of this, hospitals and health agencies rarely systematically screen for child maltreatment risk. Child maltreatment is preventable. Its prevention requires the coordinated application of interventions that address key lapses in "species-typical" mechanisms of protection of the young: caregiving knowledge and competence, resource acquisition, surrogacy (i.e., the family or adult "village" surrounding a child to assist when a parent needs help), and close surveillance of the child3. A prototypic, yet remarkably common risk scenario is that of a single parent with multiple young children, isolated by poverty, under-educated in the modeling of appropriate caregiving (or whose own experience in being parented was traumatic or deficient) and with either an untreated mental health impairment or substance use disorder. An effective, evidence-informed approach to reduce the risk of child maltreatment imposed by this set of circumstances would include nurse (or paraprofessional) home visitation, parenting education, parental mental health care, a support resource for times of crisis, and reproductive health planning. This is analogous to the level of comprehensive intervention that is afforded to patients with complex medical disorders in most health systems, encompassing cost-efficient, evidence-based interventions that could be prioritized for families at risk and coordinated by efficient, targeted case management. Yet, rarely does any family at risk receive a full complement of these necessary supports3, 8. In the US, fragmentation across health agencies, state departments, and local bureaucracies, together with a lack of ownership of systematic risk surveillance by health systems, all but ensure that almost no family at risk ever receives this level of support. The end result is that child maltreatment is perpetrated at epidemic proportions: a conservative estimate of prevalence based on official records is that, in the US, one out of every six children is a victim2. Not all children succumb to the deleterious impact of maltreatment. Rather, the effects of trauma on brain and behavioral development are moderated by factors such as timing of occurrence over the course of childhood; severity, type and chronicity of maltreatment; and genotypic variation of victims. These factors render children more or less prone to becoming overwhelmingly biologically stressed by the adverse experience. It is the phenomenon of being stressed beyond capacity to compensate or respond adaptively that is believed to be most salient in the neurobehavioral toxicity of trauma, so-called "toxic stress"9. Specific inherited profiles of temperament render some children susceptible to overwhelming anxiety in response to trauma, and others to patterns of impulsive aggression. Jonson-Reid et al5 observed dose-response effects of the number of officially reported instances of abuse/neglect on an array of child and adult mental health outcomes in an unbiased, state-wide ascertainment. An important paradox about the role of child maltreatment in the causation of psychiatric syndromes is the overarching conclusion from large twin and family studies that environmental variations – within the typical range observed in the general population – tend not to be as influential in the causation of serious mental health impairments as either genetic factors or severe environmental adversities outside of the typical range. Construed graphically, if plotting severity of adversity (X axis) against degree of psychiatric impairment (Y axis), incremental increases in adversity within the typical range result in only minimal increases along the Y axis of psychiatric impairment. But at an inflection point – that varies for each child on the basis of genetic vulnerability or resilience – the Y axis "cost" steepens with further incremental increases in adversity, and levels off (forming a sigmoid curve) at a point beyond which impairment is so pronounced that further increases in stress have negligible additional effect. Improved ability to operationalize "level of adversity" in increasingly precise ways, and thereby specify a curve for an individual child, stands to revolutionize targeted preventive intervention by ensuring that each child remains within his/her "safe zone" along these two critical axes. In the meantime, efforts to prevent the occurrence of maltreatment in all children and families with appreciable elevated risk – either for maltreatment or its consequences – represents a feasible strategy for reducing the public health burden of psychopathology. Given demonstrated progress in the ability to predict and prevent child maltreatment, health and governmental systems around the world have a new opportunity (and an ethical mandate) to deploy evidence-based elements of intervention at developmentally sensitive times during the life course, targeting multiple risks, and building on existing delivery platforms for feasibility of scale-up2,8, 10. Parents, caregivers and families need to be supported in providing nurturing care and protection in order for young children to achieve their developmental potential, and – as emphasized by Shonkoff9 – it must be understood and put into practice that healthy brain development requires not only enrichment, but protection from toxic stress. John N. Constantino Washington University School of Medicine, St. Louis, MO, USA This work was supported in part by a grant from the US Administration for Children and Families (90YR0054-04).