"The take home point is that the verbal behaviors matter," Annette Mahoney, who worked on the study, said. She's a professor of psychology at Bowling Green State University in Ohio.
"It can be easy to overlook that, but our study shows that the verbal hostility is really relevant, particularly for mothers who scream and hit, and for fathers who do either one," Mahoney told Reuters Health.
All of the kids in her study had been referred to a community clinic due to mental health or behavioral problems.
Their mothers had to be both verbally and physically abusive to increase the kids' risk for depression and behavior issues. But either kind of behavior alone from a father was sufficient to produce lasting ill effects.
The researchers realize that parents can be trapped in a vicious cycle.
Verbal abuse "has a cyclical nature to it," said Mahoney. Kids with behavioral or mental health problems can be tough to handle, she said.
Image: Parent and teenager arguing, via Shutterstock