Updated

The children of mothers with posttraumatic stress disorder (PTSD) may be at high risk of being traumatized themselves, according to a small new study in urban U.S. neighborhoods.

Inner-city kids whose mothers had PTSD experienced more traumatic events - such as neighborhood shootings, domestic violence, dog bites or car accidents - before age five than kids whose mothers were depressed or had no mental health issues, researchers found.

Mothers with a combination of PTSD and depression were also more likely to report psychologically or physically abusing their child, compared to mothers with just one of those disorders.

"The main take-home message is that when parents are suffering, their children suffer, too," said Dr. Howard Dubowitz, professor of pediatrics at University of Maryland School of Medicine in Baltimore.

"Those of us who are involved in helping to take care of kids can't ignore what problems mothers and fathers may be struggling with," added Dubowitz, who was not involved in the study.

Children exposed to trauma are themselves at greater risk of a mix of health challenges later on in life, such as obesity, drug and alcohol addictions, heart disease, suicide and mental health disorders, experts said.

"Everyone's been putting the focus on depression, even though PTSD and depression run together," said the study's lead author Claude Chemtob, director of NYU Langone Medical Center's family trauma research program.

He and his colleagues recruited 97 mothers with children between the ages three and five years old from Mount Sinai School of Medicine's pediatric primary care clinics in New York City to participate in the study.

Most mothers were from ethnic minority groups and had high school diplomas. The women all completed questionnaires designed to detect depression or PTSD symptoms. They also answered questions about violent events their children had witnessed.

The majority of mothers were not clinically depressed or suffering from PTSD, Chemtob's group reports in JAMA Pediatrics. Of the 97 mothers, 11 had diagnosable depression, six had PTSD and 10 had a combination of both.

Chemtob pointed out that the study population had slightly elevated levels of depression and PTSD diagnoses compared to national averages.

The researchers also found that mothers with PTSD and depression reported far greater parenting stress. "In short, their experience of parenting is that it is more difficult and less rewarding," Chemtob said.

Last year the American Academy of Pediatrics urged pediatricians to take steps to reduce childhood "toxic stress" that can occur when parents or caregivers suffer from poor mental health.

In the current study, the children of mothers with PTSD witnessed an average of five traumatic events.

Their peers whose mothers were only depressed or had no mood disorder experienced an average of only one traumatic event. A third group of kids with mothers suffering both PTSD and depression experienced nearly four events.

Previous research suggests that nearly half of women with PTSD may also suffer from depression.

"We know that the effects of maternal mental health difficulties can be especially problematic in early life, from pregnancy to age 5," Michelle Bosquet of Boston Children's Hospital in Massachusetts told Reuters Health in an email.

Bosquet, who was not involved in the new study, added that much previous research has focused only on depression and less is known about how PTSD may influence parenting.

Researchers noted that the study is limited by its small size.

"These results have been found among certain families," Dubowitz said. Future studies could look for the same results in different populations, such as whites, he said.

The authors encourage screening mothers for PTSD alongside depression in pediatric primary care settings. "This might be an effective way to intervene on child maltreatment," Chemtob told Reuters Health.

In his research on child abuse, Dubowitz has created a questionnaire for parents to complete before arriving for a pediatric appointment. It contains two questions to detect depressive symptoms.

"It may be most efficient to use just two questions to identify possible depression, and, in so doing, identify parents with that condition and … help them get evaluated," Dubowitz said.

"Aside from time, and time is very important, there is the whole challenge of changing health professionals' practice and behavior," he said.