Effects of Childhood Maltreatment

This research was recently summarized by my friend/colleague Ken Pope, PhD, from "Assessment of the Harmful Psychiatric and Behavioral Effects of Different Forms of Child Maltreatment", to be published soon in JAMA.  The authors are David D. Vachon, PhD, Robert F. Krueger, PhD, Fred. A. Rogosch, PhD, and Dante Cicchetti, PhD.  The following is his enlightening summary:

PLEASE NOTE: As usual, I'll include both the author's email address (for requesting electronic reprints) and a link to the complete article at the end below.

Here's how the article opens:

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Worldwide prevalence estimates suggest that child physical abuse (8.0%), sexual abuse (1.6%), emotional abuse (36.3%), and neglect (4.4%) are common.1,2 These forms of abuse and neglect are collectively referred to as child maltreatment (CM). At least 4 assumptions pervade the scientific literature on CM: (1) harmfulness (CM causes substantial harm), (2) nonequivalence (some forms of CM are more harmful than others), (3) specificity (each form of CM has specific consequences), and (4) nonuniversality (the effects of CM differ across sex and race).

The strongest assumption is that CM causes harm. In a meta-analysis, nonsexual forms of CM (physical abuse, emotional abuse, and neglect) were associated with a wide range of mental health problems, including depression, anxiety, eating disorders, substance use, and suicidal behavior.3 Evidence from research on sexual abuse is less consistent. Although early literature reviews concluded that child sexual abuse predicts a range of psychiatric outcomes,4- 6 later meta-analyses based on community samples7 and college samples8 suggested that child sexual abuse is weakly associated with later adjustment problems. Unsurprisingly, these findings are controversial9 and have been criticized10,11 and defended12,13 on several occasions.

The nonequivalence assumption is evident in the legal system, where some forms of CM are felonies but others are legal, and in the scientific literature, which focuses predominantly on sexual and physical abuse.14 However, meta-analytic data do not show appreciable differences in harm across types of CM.3 Furthermore, study-level comparisons are confounded by differences in samples and methods, and individual-level comparisons are rare and usually fail to model patterns of CM co-occurrence. The ubiquity of the assumption of nonequivalence must therefore be based on factors other than comparative evidence of harm, such as cultural mores and differences in the ability to measure and document maltreatment.

The specificity assumption is based on early studies suggesting that certain exposures may be linked to particular mental health outcomes.15,16 However, subsequent evidence suggests that various forms of CM may have nonspecific, widespread effects on mental health.13,16,17 An unanswered question is whether such widespread effects are the result of CM affecting common factors that underlie multiple psychiatric disorders.

The nonuniversality assumption has received occasional support from research showing sex differences18 and racial differences19 in outcomes related to CM, motivating some to recommend treatments tailored to sex and race.20 However, research in this area is scarce, and few studies have directly statistically tested sex or race as a moderator. Prevalence rates may differ between populations, as might various risk factors and service response variables, but the question whether the effects of CM generalize across populations remains unanswered.

To test each assumption and overcome the limitations of previous research, this study rigorously assesses multiple forms of CM, relates them structurally, and uses them to predict a broad range of ensuing maladjustment in a large, racially diverse sample of boys and girls aggregated over 27 years. We hypothesized that our results would correspond with meta-analytic evidence supporting the assumption of harm; otherwise, our results would contradict the other assumptions, including nonequivalence, specificity, and nonuniversality. That is, we hypothesized that different forms of CM would have equivalent, broad, and universal consequences. Such findings would have substantial etiologic, clinical, and legal implications.

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Here's an excerpt from the Discussion section:

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Our results suggest that physical abuse, emotional abuse, and neglect are equivalent insults that affect broad psychiatric vulnerabilities. Our results also highlight an important problem--one that may explain mixed findings in the literature on child sexual abuse. Specifically, child sexual abuse is an infrequent event that is almost always accompanied by other types of CM. This pattern of rarity and lopsided co-occurrence has several consequences. First, it poses a statistical constraint that severely attenuates the correlation between sexual and nonsexual CM. For example, if nearly all people with a given disorder are men but very few men have that disorder, then sex will be nearly uncorrelated with the disorder (despite the fact that almost all cases are in men). This constraint explains why sexual CM and nonsexual CM are weakly correlated factors in our structural model: whereas 89% of cases of sexual CM are accompanied by nonsexual CM, only 9% of cases of nonsexual CM are accompanied by sexual CM.

Second, there is no practical way to understand the specific consequences of sexual CM because its correlates may be attributed to other forms of co-occurring CM. Statistically controlling for co-occurring CM removes what little covariation is left after the attenuation caused by unidirectional redundancy, further gutting the variance in the sexual abuse variable and producing unreliable parameter estimates. Alternatively, cases of "pure" sexual abuse (without co-occurring CM) are extremely rare and unrepresentative. This intractable issue may explain why research on sexual CM produces mixed results. The infrequency of sexual CM combined with its unidirectional redundancy with nonsexual CM attenuates their correlation and undermines efforts to identify the effects of sexual abuse, which are almost certainly detrimental. As such, previous meta-analyses of the literature on child sexual abuse7,8 may produce misleading results.

This study also partially addresses a potentially confounding variable: SES. Because factors associated with low SES predict the occurrence of both CM36 and mental illness,37 low SES may explain the association between CM and psychopathologic disorders. In the current study, all children were sampled from families with low SES, attenuating this potential SES confounder. However, a different pattern of results may be found in populations with higher SES.

Sexual abuse may be an underreported type of CM that is difficult for child protection agencies to substantiate. Thus, an important limitation to overcome is collecting data on these missed cases; doing so may also help address the methodologic problem of rarity and lopsided co-occurrence. Other limitations of this study include reliance on official documentation, absence of data regarding psychopathologic disorders prior to CM, and use of psychological reports from counselors and children who only knew the participants in the camp setting.

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REPRINTS:   Robert F. Krueger, PhD, Department of Psychology, University of Minnesota, 75 E River Rd, Minneapolis, MN 55455 krueg038@umn.edu

The article is online at:

Ken Pope