(Reuters Health) - Parents who had a lot of traumatic or stressful experiences during childhood may be more likely to have kids with behavioral problems, a U.S. study suggests.

Adverse childhood experiences can include witnessing parents fight or go through a divorce, having a parent with a mental illness or substance abuse problem, or suffering from sexual, physical or emotional abuse.

These childhood experiences have been linked to what’s known as toxic stress, or wear and tear on the body that leads to physical and mental health problems that often continue from one generation to the next. But the exact effect of parents’ trauma on their children’s behavioral and emotional health isn’t fully understood.

In the current study, researchers examined data on how many different types of adverse childhood experiences (ACEs) were endured by the parents of 2,529 kids, and how often the kids experienced emotional or behavioral problems or attention issues.

Compared to children whose parents didn’t experience any ACEs, children whose parents went through one type of adverse experience in childhood were 44 percent more likely to have hyperactivity and 56 percent more apt to have emotional or mental health issues, researchers report in Pediatrics.

When parents experienced at least four ACEs, their kids were twice as likely to have hyperactivity and four times more likely to have emotional or mental health problems.

“This demonstrates one way in which all of us carry our histories with us, which our study shows has implications for our parenting and our children’s health,” said lead study author Dr. Adam Schickedanz, a pediatrics researcher at the David Geffen School of Medicine at the University of California, Los Angeles.

“Given that children’s behavioral health is so strongly influenced by severe stresses in the formative relationships and experiences of their parents, it suggests that investments made now to prevent childhood adversity could yield lasting returns for health across generations,” Schickedanz said by email.

Mothers’ experiences appeared to have a bigger impact on children’s health than fathers’ upbringings, the study found.

When mothers were exposed to one ACE growing up, their children were 85 percent more likely to be hyperactive and 92 percent more likely to have emotional or mental health problems. When mothers endured at least four ACEs, kids had triple the odds of hyperactivity and more than quintupled odds of emotional or mental health issues.

With fathers, one to three ACEs did not appear to increase their child’s risk of hyperactivity or behavioral or mental health issues. However, when fathers experienced four or more ACEs, kids were 29 percent more likely to be hyperactive and more than twice as likely to have behavioral or mental health problems.

The study was not a controlled experiment designed to prove whether or how parents’ childhood experience might directly impact the physical or mental health of their kids. Another limitation is that researchers were not able to assess individual resilience to adversity, which might influence how ACEs impacted parents or how these experiences affected the next generation.

Even so, the results add to evidence suggesting that ACEs can have long-lasting effects on families across generations, said Alonzo Folger, a researcher at the University of Cincinnati College of Medicine in Ohio who wasn’t involved in the study.

Among other things, chronic exposure to ACEs during childhood may make it harder for parents to bond with children and cope with normal but often stressful and emotionally taxing behaviors of infants and toddlers, Folger said by email.

“We increasingly recognize the disruptive nature of toxic stress caused by early life adversity and the importance of early intervention,” Folger said.

Parents should tell their child’s doctor about any family history of ACEs, and if they don’t bring it up, then pediatricians should initiate this conversation, said Dr. Ricardo Quinonez, chief of pediatric medicine at Texas Children’s Hospital in Houston.

“This discussion may lead to early interventions to prevent the negative consequences of mental health in their own children,” Quinonez, who wasn’t involved in the study, said by email.

SOURCE: bit.ly/2LrW7jP Pediatrics, online July 9, 2018.