New York, Jul 9 (IANS): Experiencing childhood trauma resulting from separation of parents or witnessing violence at home may have long-term effects, suggests a new study that found that ill effects of such stress can reach the kids of the sufferer.

The results, published in the journal Pediatrics, showed that the children of parents who themselves had four or more adverse childhood experiences were at double the risk of having attention deficit hyperactivity disorder and were four time more likely to have mental health problems.

"This is the first research to show that the long-term behavioural health harms of childhood adversity extend across generations from parent to child," said study lead author Adam Schickedanz from University of California, Los Angeles, US.

For the study the team analysed information from a US national survey containing information from four generations of families.

The researchers looked at whether the parents were abused, neglected or exposed to other family stress or maltreatment while growing up and analysed information on their children's behaviour problems and medical diagnoses of attention deficit disorder.

The types of childhood hardships analysed for the research included divorce or separation of parents, death of or estrangement from a parent, emotional, physical or sexual abuse, witnessing violence in the home, exposure to substance abuse in the household or parental mental illness.

The findings showed that a mother's childhood experiences had a much stronger adverse effect on a child's behavioural health than the father's experiences.

"If we can identify these children who are at a higher risk, we can connect them to services that might reduce their risk or prevent behavioural health problems," Schickedanz explained.