FRIDAY, Dec. 9 (HealthDay News) -- Children born to mothers with postpartum depression are at increased risk for mental health problems, but a hormone called oxytocin may reduce the risk, according to a new study.

Oxytocin, which is produced naturally in the body and has been associated with feelings of love and trust, may help protect kids from the negative effects of maternal depression, the researchers found. A synthetic version of the hormone is available as medication.

In the study, Israeli researchers looked at 155 mother-child pairs. By the time they were 6 years old, 60 percent of children born to mothers who were consistently depressed for the first year after giving birth had mental health problems, mainly anxiety and conduct disorders.

Among the 6-year-old children whose mothers did not have postpartum depression, only 15 percent had mental health problems, the investigators noted.

The study also found that children born to mothers with extended postpartum depression were less verbal and had lower levels of playfulness and creativity, less engagement with their mothers, diminished social involvement, and less empathy for the pain and distress of others.

These children and their mothers also had disordered functioning of the oxytocin system, as shown by lower levels of oxytocin in their saliva and a variant on the oxytocin receptor gene that increases the risk of depression, according to study leader Ruth Feldman, a professor in the psychology department and the Gonda Brain Sciences Center at Bar-Ilan University, and colleagues.

Among the children born to depressed mothers, the 40 percent who did not have mental disorders by age 6 had normal functioning of the oxytocin system and normal levels of oxytocin in their saliva.

The study was slated for presentation Thursday at the annual meeting of the American College of Neuropsychopharmacology, in Hawaii.

"We found the functioning of the oxytocin system helps to safeguard some children against the effects of chronic maternal depression," Feldman said in a college news release. "This study could lead to potential treatment options for postpartum depression and methods to help children develop stronger oxytocin systems."

Because this study was presented at a medical meeting, the data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.

More information

The Nemours Foundation has more about postpartum depression.