The study by Teicher and colleagues in this issue (
1) opens another window on how adverse interpersonal experiences hurt children. In many respects, however, the results reveal a disturbingly familiar picture similar to that first sketched by the seminal Adverse Childhood Experiences study (
2). In the Teicher et al. study, as in prior research, there is evidence of a dose-dependent relationship between the severity of the childhood adversity and negative adult outcomes. Adverse childhood experiences are associated with a broad array of comorbid symptoms, including anxiety, depression, somatization, anger and hostility, dissociation, and substance abuse, with somewhat different outcomes in women and men. Finally, as a number of prior studies have found, there is a graded relationship between level of childhood adversity and structural changes in the brain.
What Teicher and colleagues in the Developmental Biopsychiatry Research Program at McLean Hospital add to this picture is evidence for an interaction between the child's age at the time of peer verbal abuse and a range of symptomatic outcomes. The middle school years appear to be an especially sensitive period for the pernicious effects of peer verbal abuse. The investigators found interactions between peer verbal abuse and gender, with females scoring higher on measures of dissociation and “limbic irritability” and males reporting greater drug use. It is interesting that the effects attributable to peer verbal abuse are essentially equivalent to those found in subjects with histories of parental verbal abuse but not other forms of abuse or neglect.
Peer verbal abuse, sometimes dismissed as an inevitable rite of passage, joins the growing list of childhood adversities, including physical and sexual abuse, neglect, exposure to domestic violence, and parental depression, shown to have long-term detrimental effects, extensive psychiatric comorbidity, and significant effects on brain development and cognitive function. It is important to recognize this potency as new forms of peer victimization, such as cyberbullying, are dramatically increasing the scale and distance from which peers can harass and humiliate each other. Once posted on the web, these very public insults and virtual assaults can “go viral,” taking on lives of their own and persisting long after they would have otherwise lost their immediacy. Child pornography victims whose images continue to circulate on the Internet describe a sense of perpetual victimization; it is likely that this will be as true for victims of cyber-bullying. Once posted on the web, the lies, slurs, insults, and humiliations will be linked to them for the foreseeable future.
The commonality of symptoms and outcomes among the various forms of childhood adversity studied to date suggests that the underlying traumatogenic mechanisms are similar or at least share common developmental pathways. We can hope that a corollary would be that proven treatments for one type of childhood adversity could be successfully adapted for others. To some extent this is proving true, as evidence-based child trauma treatments such as trauma-focused cognitive-behavioral therapy demonstrate efficacy in heterogeneous groups of traumatized youth (
3).
The mechanistic linkages between developmental neurobiology and problematic behavior emerging from studies of the effects of childhood adversity provide a new perspective into the perennial nature-nurture question. Although the number of studies in this area is relatively low compared to the numbers in many areas of psychiatric research, the findings are remarkably robust and merit a significant increase in support. Epigenetics, the functional modification of the genome without changing nucleotide sequences, is one possible avenue through which early adverse environmental and interpersonal experiences may produce their lifelong and potentially heritable alterations in critical stress response systems and even personality (
4). Preliminary research with foster children (
5) and parent-child psychotherapy (
6) indicates that some of the biological dysregulation and cognitive deficits can be reversed—at least in preschoolers.
Prevention, however, remains the most cost-effective approach for all forms of early childhood adversity. First-generation models such as home visiting (
7) and Triple P (Positive Parenting Program) (
8) have demonstrated efficacy and cost-effectiveness. But they have yet to be deployed on a scale sufficient to move the national needle significantly. Data on dose thresholds, gender differences, and developmental periods of heightened vulnerability, such as reported by Teicher et al., inform the design and timing of preventive interventions.
The payoff from implementing effective prevention programs on a scale large enough to tangibly reduce the rates of maltreatment and family dysfunction could be enormous. Green and colleagues (
9) found that almost one-half (44.6%) of all childhood-onset psychiatric disorders and one-quarter to one-third (25.9%–32%) of adult-onset cases are associated with combinations of childhood maltreatment and family dysfunction. Other studies and meta-analyses have shown that child maltreatment and family dysfunction make strong contributions to major medical conditions, including costly public health problems such as substance abuse and HIV risk, as well as to the leading causes of death (
2,
10). Much of this is secondary to health risk behaviors such as smoking, substance abuse, sexual promiscuity, and poor diet, but some appears to be the result of biological alterations in immune and inflammatory processes. In addition to reducing mental and medical health problems, significantly preventing maltreatment and childhood adversity should decrease crime—both victimization and perpetration—and improve academic and occupational attainment (
10). These benefits would be passed on to the next generation in the form of improved parenting and healthier home environments. Our challenge is to implement existing evidence-based or -informed prevention programs on a scale sufficient to change the public health landscape and then to continually improve these programs as they provide services. The research methods and quality improvement tools to accomplish this exist; we must muster the vision, public and professional support, and resources to make it happen.