Children who are maltreated are much more likely to have physical and mental health problems later on. They face a higher risk of suicide and of getting in trouble with the law.
But there's a big gap between the number of people who say they were abused or neglected as children and the official rate of annual confirmed cases, which runs about 1 percent.
That may be because looking at annual numbers alone understates a child's risk of maltreatment throughout childhood, researchers say. By that measure, 12.5 percent of children have experienced at least one episode of abuse or neglect by age 18, a study published Monday finds.
The numbers are worse for children in minority groups, with 21 percent of African-American children, 14.5 percent of Native Americans and 13 percent of Hispanic children affected.
Just looking at the 1 percent annual number makes it easy for people to think that maltreatment affects just a few children with bad parents, says Christopher Wildeman, an associate professor of sociology at Yale University who led the study.
This study, which was published in the journal JAMA Pediatrics, used confirmed cases of maltreatment in a national child abuse database from 2004 to 2011.
Almost 6 million children were included. The vast majority of cases, about 80 percent, involved neglect. In 2011, 18 percent were victims of physical abuse and 9 percent sexual abuse, according to state and local child protective services reports.
The risk was highest in the early years of a child's life, with 25 percent of first reports of maltreatment coming before a child turned 2. All told, 6 percent of children had been maltreated by the age of 5.
And sadly, parents and other relatives pose the greatest risk. Most victims, 81 percent, were maltreated by a parent, according to the 2011 data. About 6 percent of perpetrators were nonparent relatives; 4 percent were unmarried partners of parents; and just 3 percent were unrelated adults.
Child protective services are good at limiting maltreatment among children who have been neglected or abused, Wildeman says, but not so much at helping avoid that maltreatment in the first place. "If you could address that immediate time when parents are stressed out and broke, and the child is crying," he says, it could lower the risk of abuse in early childhood.
A variety of preventive efforts, from home nurse visits for first-time parents to training in how to manage children's behavior, have been tested over the years and shown to reduce a child's risk of maltreatment. But the programs aren't widely funded.