That holds true even after accounting for factors like poverty and family stress, according to a study in the new issue of the journal Archives of Pediatrics and Adolescent Medicine.
Although the results echo common sense and earlier findings, the researchers say their study has advantages over previous research. Some past work relied on surveys from child protective service agencies, for example, and thus included many children from troubled home lives.
But the new results come from three communities and include a relatively small fraction of children from broken homes, says study lead author Jennifer Lansford, a researcher at Duke University's Center for Child and Family Policy. What's more, as a prospective study that tracked children for a dozen years, it didn't have to rely on the memories of adults who may have been abused as children.
"I think we can speak more strongly about the long-term effects of abuse rather than the circumstances surrounding abuse," Lansford says.
An estimated three million cases of suspected child abuse and neglect are reported to officials each year. Of those, about one million are ultimately confirmed. Roughly half the cases involve neglect, while 25 percent are physical assaults and 10 percent are sexual assaults.
Researchers are learning that the connection between abuse and misbehavior later in life is complex and not always a case of cause and effect.
For instance, scientists recently reported that boys abused in early childhood were less likely to turn to crime as young adults if they had a normal version of a gene controlling a key brain molecule. However, abused boys were far more likely to become embroiled in crime as adults if their version of that gene was shortened.
Lansford and her fellow researchers at Auburn University and Indiana University followed 585 boys and girls from the summer before they entered kindergarten through the end of 11th grade. Of those, 79 percent stayed in the study to its completion.
Interviews with mothers at the start of the study revealed that 69, or nearly 12 percent, of the children had been physically abused before entering kindergarten. Follow-up interviews with the women and the children 12 years later revealed that abused children, especially boys, showed many more signs of trouble than their well-treated classmates.
Victims of abuse missed 50 percent more school and were less likely to say they were headed to college. They also were more prone to significant problems with aggression, depression and anxiety, as well as delusional thinking and attention woes.
When surveyed about their own behavior, 74 percent of the abused children, versus 43 percent of the non-abused children, reported at least one of seven serious behavior problems: gang membership, getting pregnant or impregnating someone, being suspended from school, having trouble with the police, running away, or suffering serious emotional difficulties. And 21 percent of the abused children reported three of these problems, compared to seven percent of the other children.
Neither group was more prone to drug use, Lansford says.
Kevin Kirkpatrick, a spokesman for Prevent Child Abuse America, an advocacy group in Chicago, says the Duke study isn't surprising. But, he adds, "It is extremely compelling evidence of what we've been saying for years -- that effects of child abuse can impact a person's life well into adulthood."
In an unrelated study also in the pediatrics journal, British researchers report that school-based programs can reduce violent behavior in aggressive children. They analyzed 44 previous studies of such interventions, concluding that those that stressed "nonresponse" skills -- keeping children from reacting to an aggressor -- had longer-lasting impact than those focusing on relationship skills.
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