Sept. 5 (UPI) -- A new study by the University of Southern California found that fathers face a higher risk of experiencing postpartum depression if testosterone levels drop nine months after the baby is born.
The study, published in the September edition of Hormones and Behavior, consisted of 149 couples in the Community Child Health Research Network showed that men have biological responses to fatherhood.
"We often think of motherhood as biologically driven because many mothers have biological connections to their babies through breastfeeding and pregnancy," Darby Saxbe, assistant professor of psychology at USC Dornsife College of Letters, Arts and Sciences, said in a news release. "We don't usually think of fatherhood in the same biological terms. We are still figuring out the biology of what makes dads tick.
"We know that fathers contribute a lot to child-rearing and that on the whole, kids do better if they are raised in households with a father present. So, it is important to figure out how to support fathers and what factors explain why some fathers are very involved in raising their children while some are absent."
For the study, mothers were age 18 to 40, low-income and African-American, white or Latina women who had given birth to their first, second or third child. Roughly 95 percent of the fathers who participated in the study lived with the mothers.
The couples were visited three times in the first two years after birth: around two months after the child was born, about nine months after birth and about 15 months after birth. The couples were interviewed and at the nine-month visit, fathers gave saliva samples that were taken three times a day.
Study participants were interviewed about depressive symptoms, relationship satisfaction, parenting stress and any potential intimate partner aggression.
Researchers found that a father's low testosterone affects women by lessening symptoms of depression themselves nine to 15 months after birth.
Conversely, high testosterone levels in men increased the risk of experiencing stress from parenting and lead to a higher risk of men showing emotional, verbal or physical aggression to toward their partners.
"One take-away from this study is that supplementing is not a good idea for treating fathers with postpartum depression," Saxbe said. "Low testosterone during the postpartum period may be a normal and natural adaptation to parenthood."