A 12-Year Prospective Study of the Long-term Effects of Early Child Physical Maltreatment on Psychological, Behavioral, and Academic Problems in Adolescence
Abstract
Objective
To determine whether child physical maltreatment early in life has long-term effects on psychological, behavioral, and academic problems independent of other characteristics associated with maltreatment.
Design
Prospective longitudinal study with data collected annually from 1987 through 1999.
Setting and Participants
Randomly selected, community-based samples of 585 children from the ongoing Child Development Project were recruited the summer before children entered kindergarten in 3 geographic sites. Seventy-nine percent continued to participate in grade 11. The initial in-home interviews revealed that 69 children (11.8%) had experienced physical maltreatment prior to kindergarten matriculation.
Main Outcome Measures
Adolescent assessment of school grades, standardized test scores, absences, suspensions, aggression, anxiety/depression, other psychological problems, drug use, trouble with police, pregnancy, running away, gang membership, and educational aspirations.
Results
Adolescents maltreated early in life were absent from school more than 1.5 as many days, were less likely to anticipate attending college compared with nonmaltreated adolescents, and had levels of aggression, anxiety/depression, dissociation, posttraumatic stress disorder symptoms, social problems, thought problems, and social withdrawal that were on average more than three quarters of an SD higher than those of their nonmaltreated counterparts. The findings held after controlling for family and child characteristics correlated with maltreatment.
Conclusions
Early physical maltreatment predicts adolescent psychological and behavioral problems, beyond the effects of other factors associated with maltreatment. Undetected early physical maltreatment in community populations represents a major problem worthy of prevention.
Annually, according to the United States Department of Health and Human Services (Washington, DC), approximately 3 million children are referred to local child protective service agencies as possible victims of physical abuse, emotional abuse, sexual abuse, or neglect.1 Of these, approximately 25% of cases involve physical abuse. The number of reported cases is presumed to underestimate the actual prevalence and incidence of child maltreatment.2 Despite the scope of this problem, the long-term effects of early physical maltreatment remain unclear.
Retrospective accounts of adolescents and adults who had been abused when they were children suggest that physical maltreatment can have long-term negative consequences.3,4 However, because participants in retrospective studies generally are selected from clinical samples in treatment, it is unclear whether they accurately represent the population that had been maltreated as children.5,6 It is possible that relatively few adolescents and adults who had been maltreated as children continue to experience problems and that it is only a small proportion of those who do that end up in treatment and, consequently, retrospective studies of abuse.
Cross-sectional and short-term longitudinal studies have demonstrated that physical maltreatment is related to problems that arise in close temporal proximity to the occurrence of the abuse, such as juvenile delinquency, psychopathology, and disrupted social relationships.7,8 It is not clear from these studies, however, whether early physical maltreatment plays an enduring role in the development of later adjustment problems in adolescence or whether negative outcomes are the temporary result of trauma that will diminish in importance over time. Some researchers have argued that associations between abuse and adjustment problems can be explained by reporting biases because many studies of the effects of physical maltreatment use samples for which maltreatment is identified by referral to social service agencies.6 Of the community-wide population of maltreated children, those who are referred may represent a biased, more problematic subgroup. Also, because the effects of interventions provided by these agencies are themselves unknown, studies using these types of samples confound the effects of maltreatment and the effects of institutional interventions.9 Other researchers have contended that associations between physical abuse and later adjustment problems can be accounted for by confounding factors, such as poverty and family stress.5,10
To address the question of whether physical maltreatment early in life has long-term effects on psychological, behavioral, and academic outcomes independent of other characteristics associated with maltreatment, prospective longitudinal research with nonreferred community, rather than clinical, samples is needed. Because a number of ecological risk factors (eg, poverty, family stress) and child characteristics (eg, difficult temperament) are empirically associated with physical maltreatment, it is important to control for these correlates of maltreatment statistically to determine whether maltreatment per se has effects on later outcomes above and beyond the effects of other risk factors.10,11 In addition, because gender and ethnicity affect individuals' risk for particular types of problems, an important question is whether maltreatment affects long-term outcomes in similar ways for boys and girls and for members of different ethnicities.
This study is a prospective investigation of a community sample first identified when the participants were about 5 years old. Initial findings revealed that the physically maltreated children in the sample were at risk for aggressive behavior problems on school entry.12,13 To our knowledge, this article is the first report of adolescent outcomes of early physical maltreatment in this sample.
Results
Two (maltreated vs not maltreated) × 2 (gender) × 2 (white vs minority) analyses of variance were conducted to examine adolescents' adjustment as a function of early physical maltreatment, taking into account gender and ethnicity. The main effects of maltreatment are presented in the Table. The first 3 columns show the main effects of maltreatment without controlling for other risk factors associated with maltreatment. The second 3 columns depict the main effects of maltreatment, controlling for ecological and child risk factors.
Table
Differences Between Maltreated and Nonmaltreated Children in Academic, Psychological, and Behavioral Problems in Adolescence*
| Unadjusted | Covariates Adjusted | |||||
|---|---|---|---|---|---|---|
| Outcome | Not Maltreated | Maltreated | F | Not Maltreated | Maltreated | F |
| Grades 9-11 Official School Records (Not Maltreated, n = 387; Maltreated, n = 50) | ||||||
| Mathematics grade (1 = F, 13 = A) | 8.06 (0.17) | 6.91 (0.49) | 3.24 | 7.65 (0.25) | 7.39 (0.64) | 0.15 |
| Language arts grade (1 = F, 13 = A) | 8.64 (0.17) | 7.04 (0.54) | 7.63† | 8.21 (0.23) | 7.70 (0.59) | 0.70 |
| Total mathematics percentile | 67.97 (1.07) | 64.51 (3.07) | 3.37 | 67.55 (1.59) | 63.12 (4.42) | 0.96 |
| Total language arts percentile | 70.49 (1.00) | 64.73 (3.21) | 5.58‡ | 70.10 (1.51) | 65.72 (3.98) | 1.14 |
| No. of days absent | 10.27 (0.65) | 20.47 (3.06) | 21.63§ | 12.40 (0.94) | 19.33 (2.36) | 8.14† |
| No. of times suspended | 0.58 (0.11) | 1.19 (0.38) | 5.65‡ | 0.73 (0.15) | 1.23 (0.38) | 1.64 |
| Grade 11 Mother Reports (Not Maltreated, n = 392; Maltreated, n = 52) | ||||||
| Subscales | ||||||
| Aggression | 5.72 (0.27) | 10.02 (1.01) | 23.64§ | 6.06 (0.40) | 8.15 (0.91) | 4.80‡ |
| Anxiety/Depression | 3.07 (0.16) | 5.73 (0.75) | 34.40§ | 2.67 (0.27) | 5.32 (0.61) | 16.89§ |
| Dissociation | 1.68 (0.11) | 3.38 (0.43) | 28.63§ | 1.58 (0.16) | 2.80 (0.37) | 10.01† |
| Delinquent Behavior | 2.02 (0.12) | 3.40 (0.42) | 17.80§ | 1.87 (0.19) | 2.59 (0.44) | 2.51 |
| Posttraumatic Stress Disorder | 4.70 (0.21) | 8.22 (0.77) | 31.19§ | 4.34 (0.33) | 7.01 (0.75) | 11.50† |
| Social Problems | 1.35 (0.09) | 3.11 (0.40) | 33.08§ | 1.35 (0.16) | 2.65 (0.36) | 12.25† |
| Thought Problems | 0.32 (0.04) | 0.84 (0.19) | 22.74§ | 0.27 (0.06) | 0.70 (0.14) | 9.45† |
| Social Withdrawal | 2.32 (0.12) | 3.98 (0.45) | 18.06§ | 2.18 (0.19) | 3.31 (0.43) | 6.23‡ |
| Grade 11 Adolescent Reports (Not Maltreated, n = 405; Maltreated, n = 53) | ||||||
| No. of drugs tried | 1.18 (0.07) | 1.00 (0.17) | 0.02 | 0.95 (0.11) | 0.69 (0.26) | 0.89 |
| No. of behavior problems | 0.28 (0.03) | 0.45 (0.10) | 9.04† | 0.29 (0.04) | 0.36 (0.10) | 0.40 |
| Chances will go to college (1 = low, 5 = high) | 4.36 (0.05) | 3.56 (0.18) | 22.16§ | 4.36 (0.07) | 3.79 (0.17) | 11.01§ |
As shown, adolescents who had been maltreated early in life had lower grades and standardized test scores in language arts, were absent from school almost twice as many days, and were suspended from school more than twice as many times as adolescents who had not been maltreated. However, with the exception of school absences, all of these effects could be accounted for by risk factors associated with maltreatment rather than maltreatment per se.
In grade 11, mothers reported that adolescents who had experienced early maltreatment had levels of aggression, anxiety/depression, dissociation, delinquent behaviors, PTSD, social problems, thought problems, and social withdrawal that were on average twice as high as those of their nonmaltreated counterparts. The effects of maltreatment on all of these psychological and behavioral problems as reported by adolescents' mothers could not be explained away by other risk factors (with the lone exception of delinquent behavior). However, adolescents who had been maltreated did not differ from those who had not been maltreated on these dimensions based on their own reports; these variables are not shown in the Table and were excluded from further analyses. On the Adolescent Behavior Questionnaire, adolescents who had been maltreated reported more behavior problems than did their nonmaltreated counterparts (although this effect was accounted for by other risk factors rather than abuse per se) and were less likely to anticipate attending college (a little better than a 50% chance vs a high or very high chance) even after controlling for other risk factors.
The magnitude of the effects of early maltreatment on several adolescent problems depended on the adolescent's gender and ethnicity. Maltreatment × gender and maltreatment × ethnicity interactions were tested for all dependent variables; only interactions significant after controlling for ecological and child covariates are shown in the figures. As shown in Figure 1, boys and girls who had been maltreated were more likely to experience adjustment problems compared with nonmaltreated adolescents, but the effects of early maltreatment were stronger for girls than for boys. Although not shown in Figure 1, significant maltreatment × gender interactions for dissociation (F1,377=5.40, P<.05), PTSD (F1,377=14.39, P<.001), social problems (F1,377=5.99,P<.05), thought problems (F1,377=7.82, P<.01), and social withdrawal (F1,377=5.48, P<.05) replicated the pattern of findings depicted for aggression and anxiety/depression. Figure 2 illustrates all significant maltreatment × ethnicity interactions, controlling for ecological and child covariates. This figure indicates that for school absences, the negative effect of maltreatment was stronger for minority than white children. In addition, minority adolescents who were maltreated were suspended more often and had more behavior problems than did minority adolescents who were not maltreated; the effect was in the opposite direction but not significant for white adolescents.
Representative significant maltreatment × gender interactions from analyses of covariance. School absences were obtained from official school records. Aggression and Anxiety/Depression subscale scores are from the mothers' reports. Note: Although not shown here, interactions were significant for subscales of Dissociation, PTSD, Social Problems, Thought Problems, and Social Withdrawal. These effects replicated those shown for Aggression and Anxiety/Depression. The bar represents the group mean with SE.
Significant maltreatment × ethnicity interactions from analyses of covariance. School absences and suspensions were obtained from official school records. Behavior problems were determined from adolescent reports. The bar represents the group mean with SE.
These findings indicate that physical maltreatment in the first 5 years of life places a child at risk for a variety of psychological and behavioral problems during adolescence. Although on average, adolescents who had been maltreated experienced more problems than did their nonmaltreated counterparts, one may wonder whether the same group of children who had been maltreated displayed a pervasive set of maladaptive outcomes or whether different maltreated children display different maladaptive outcomes. To examine this question, we created a variable reflecting the number of problems adolescents experienced, including (1) aggression at clinically deviant levels and (2) anxiety/depression at clinically deviant levels (each 1 SD or more above the nationally normed mean as recommended by Achenbach18); (3) school suspension; (4) trouble with the police; (5) pregnancy or impregnating someone; (6) running away from home; and (7) gang membership. Thus, adolescents could experience as few as 0 or as many as 7 problems.
As shown in Figure 3, cross-tabulations of this problem count by early maltreatment revealed that 74% of adolescents who had been maltreated experienced at least 1 adjustment problem compared with only 43% of nonmaltreated adolescents. Twenty-one percent of maltreated adolescents experienced 3 or more problems compared with 7% of nonmaltreated adolescents. Thus, maltreatment in the first 5 years of life almost doubles the risk of any problem and triples the risk of experiencing problems in multiple domains during adolescence (χ23 = 26.11, P<.001).
Comment
This prospective study of a community-based sample provides support for the role of physical maltreatment in the first 5 years of life in the development of psychological and behavioral problems during adolescence, above and beyond other risk factors related to maltreatment. It does not seem to be the case that the effects of early physical maltreatment on psychological and behavioral problems are short-lived. Rather, the effects persist over at least a 12-year period. The effects range from externalizing to internalizing outcomes and touch 3 of 4 children who had been maltreated. The long-term effects of early physical maltreatment seem to be worse for girls than for boys and for minority than white adolescents, although the latter finding should be interpreted with caution because the sample of maltreated minority children was small. If replicated, this finding regarding ethnic differences in the effects of physical maltreatment will contribute to a growing body of literature on culture-specific ways in which parenting behaviors may affect child outcomes. There is evidence that parents' use of physical discipline is related to problem behaviors for European American children but that there is no relation between physical discipline and problem behaviors for African American children.23,24 Our findings suggest that this link is limited to physical discipline and does not apply to physical maltreatment.
Because these effects were found in a community rather than clinical sample, it cannot be argued that differences between maltreated and nonmaltreated children were distorted by including only cases of maltreatment serious enough to have required intervention. Furthermore, although 13 of the 69 maltreated children did have experiences with social service agencies, most of the sample did not; we have minimized the confounding of experiences with social service agencies and the experience of maltreatment by not drawing the sample from cases involved with child protective services. Finally, because this is a prospective study, our findings are not inflated by retrospective biases. All of these methodological advances address limitations in previous research on the effects of child physical maltreatment.5,6,9
An inherent limitation of correlational studies is that without random assignment, which obviously cannot be implemented in comparisons of children who have and have not been maltreated, the possibility that omitted variables are responsible for the observed associations can never be eliminated entirely. For example, physical maltreatment is sometimes comorbid with emotional abuse, sexual abuse, or neglect. We did not assess, and therefore cannot control for, these other types of maltreatment. Particularly in the case of academic achievement and problems, many of the effects of maltreatment were accounted for by risk factors that we did assess and that are correlated with the experience of maltreatment. Physical maltreatment per se seemed less important in the prediction of academic outcomes than the constellation of other risk factors associated with maltreatment. However, because these other risk factors reflect real circumstances of maltreated children's lives, maltreatment should not be assumed to be unimportant in the development of academic achievement or conduct at school.
An additional limitation of this study is that the distinction between children who had been maltreated and those who had not was made without knowledge of the chronicity, severity, or timing of the maltreatment. One would expect more psychological, behavioral, and academic problems for children whose history was characterized by maltreatment that was chronic, severe, or both. Furthermore, maltreatment classification was made on the basis of maltreatment within the first 5 years of life. There is evidence that maltreatment in early childhood is more strongly related to subsequent adjustment problems than is later maltreatment25; thus, focusing on the effects of maltreatment during this period is of particular interest. Nevertheless, in our analyses, children who were not maltreated in their first 5 years but were subsequently maltreated would have been classified with the nonmaltreated participants. Including these children in the nonmaltreated group would likely have the effect of attenuating differences between the nonmaltreated and maltreated groups. Our findings of differences between them are, therefore, especially impressive.
Although maltreated adolescents and nonmaltreated adolescents did not differ in their self-reported psychological and behavioral problems on the Youth Self-Report Form of the Child Behavior Checklist, they did differ in their self-reported likelihood of attending college and, before controlling for the covariates, in the number of behavior problems they experienced. However, mothers reported more differences between the maltreated and nonmaltreated adolescents in grade 11 than did the adolescents themselves. Because mothers were also the source of information about the children's abuse status before kindergarten, one must consider the possible effects of method variance on these findings. Nevertheless, it is impressive that early physical maltreatment remained a significant predictor of a range of psychological and behavioral problems after controlling for other important child and family risk factors. Further research will be needed to determine whether early emotional abuse, sexual abuse, and neglect similarly affect long-term adjustment and whether these findings generalize to reports of adjustment made by other individuals.
A task facing researchers is to elucidate psychological, social, and biological mechanisms through which the adverse effects of physical maltreatment occur. Because the adverse effects are wide-ranging, it is likely that characteristics of children will moderate outcomes. We doubt that the risks associated with physical maltreatment are engendered through a single instance of trauma. Rather, we believe that the mechanisms through which risk operates are likely to include (1) impaired relationships with adults and peers that preclude maltreated children from developing social competencies; (2) acquired social-cognitive problems, such as hostile attributional biases and problem-solving deficits; and (3) acquired physiological emotion dysregulation, which impairs intrapersonal as well as interpersonal functioning. Future studies are needed to support or refute these hypotheses.
A task facing practitioners and social service system managers is to design treatments for physically maltreated young children that will be effective in preventing the maladaptive outcomes for which they are at risk. No such treatment has yet been documented through rigorous tests. Public health practitioners should also try to discover noniatrogenic ways of screening and detecting young children who have been physically maltreated so that effective treatments can reach this at-risk population. Finally, the task facing policy makers is to create conditions across society that reduce the likelihood of physical maltreatment occurring in the first place. The findings reported here suggest that this need is urgent and will affect the next generation of adolescents.
Acknowledgments
The Child Development Project has been funded by grants MH42498 and MH56961 from the National Institute of Mental Health, Bethesda, Md, and HD30572 from the National Institute of Child Health and Human Development, Bethesda.
We are grateful for the ongoing dedication of the Child Development Project participants and research staff.
Footnotes
Portions of this research were presented at the biennial meeting of the Society for Research in Child Development, Minneapolis, Minn, April 20, 2001.



