Women who have strong support from their families during pregnancy appear to be less likely to experience depression after giving birth, according to a UCLA study published today.

“Our results, and those of other scientists, suggest that low or absent support is a significant risk factor for postpartum depression and that strong support is a protective factor,” said Jennifer Hahn-Holbrook, lead author of the research.

Hahn-Holbrook, a UCLA National Institute of Mental Health postdoctoral scholar in psychology and a fellow at UCLA’s Institute of Society and Genetics, said the research involved 210 pregnant women of different ethnicities and socioeconomic backgrounds, who were surveyed three times during pregnancy–at 19, 29 and 37 weeks–and then eight weeks after giving birth.

The women were asked in interviews about how much support they received from their families and the child’s father and about their symptoms of depression.

In addition, blood samples from all participants were analyzed to assess their levels of placental corticotropin-releasing hormone–pCRH–a stress hormone released from the placenta.

After taking into account factors such as age, education and income, Hahn-Holbrook and her colleagues discovered that pregnant women who reported the greatest support from their families had lower levels of depressive symptoms. They also had the least dramatic increases in pCRH and the lowest absolute levels of pCRH in the third trimester of pregnancy.

“Now we have some clue as to how support might ‘get under the skin’ in pregnancy, dampening down a mother’s stress hormone and thereby helping to reduce her risk for postpartum depression,” Hahn-Holbrook said.

The study was published in the online edition of the journal Clinical Psychological Science.