Oxytocin is a hormone that is critical to motherhood. During labor, the release of large amounts of oxytocin stimulates and strengthens contractions. It also helps us trust and feel close to others, and helps women bond with and care for their babies (which may be why it's called the 'love hormone').
And now a recent study in the American Journal of Psychiatry suggests that this multipurpose brain chemical could also affect the long-term mental health of mothers and their children.
Psychologists at Bar-Ilan University in Israel followed nearly 2,000 women (starting two days after they gave birth) and evaluated whether they had symptoms of depression six and nine months after giving birth, and then again six years later.
Out of the original group, the researchers identified 46 women who had symptoms of depression two days after childbirth that lasted throughout the first six years of their child's life. They compared these women to 103 women who did not have depression during the same period. Although there were women in the sample group who had depression for a shorter period of time (a few months or a year), researchers wanted to study the small subset of mothers who were chronically depressed for the whole six years, a condition the researchers believe is connected to oxytocin levels.
"We wanted to look at oxytocin among these women because it is the 'birth hormone' that provides the foundation for a lot of what we do as humans [including] maternal-infant gaze [how much moms focus on and engage with their babies] attachment, and affection," says Ruth Feldman, PhD, and a study author.
The link between depression and oxytocin
Feldman and her colleagues found that women with chronic depression had lower levels of oxytocin when their children were 6 years old than the women who had not experienced depression since childbirth. However, they were not able to measure oxytocin levels among the women before their children were 6 years old, so it's unclear how the hormone was related to the women's mood during the postpartum period, or whether it could have affected how they interacted with their babies.
The researchers also measured oxytocin levels among the children and fathers and found that these mirrored mothers' oxytocin levels. Although the reasons for the similarities are unclear, the oxytocin levels of children could have been low because they may not have received the kind of care that stimulates oxytocin production.
The researchers studied videos of the mothers interacting with their children and found that mothers with lower oxytocin levels gave their children fewer affectionate touches during the taped sessions. It's also possible the children inherited genes from their mother that led to low oxytocin levels, or that both factors contribute.
The possible effect on children
The children of chronically depressed mothers also seemed to have a higher rate of anxiety disorders than those whose mothers were not depressed during the six-year period. Attention deficit hyperactivity disorder and oppositional behavior were more common as well.
However, at least one factor appeared to reduce a child's risk of developing emotional difficulties if the mother had serious depression. The research team examined a gene that has been linked to oxytocin levels. They found that children of depressed mothers were less likely to have a behavioral problem if their mothers had a variation in that gene that could help bolster their oxytocin levels. The researches speculate that the children may have inherited the variant, helping them maintain higher oxytocin levels and giving them some genetic protection from growing up with a mother (and possibly a father) who suffered from chronic depression.
Moms need help
"If a mom is struggling with depression through the first six years, that mom and her family need help," says Alison Stuebe, MD, an assistant professor of maternal-fetal medicine at the University of North Carolina School of Medicine. That's the most important message she hopes women get from this study. "It's intriguing to think that oxytocin, which is involved in bonding and social relationships, may somehow be involved in [a] mom's chronic depression, but it needs to be studied more," Stuebe says.
"The hopeful message for mothers is that there is effective treatment for PPD and depression in general, and that moms who think they are having symptoms should seek help," Stuebe adds.
Most women in the study did not receive treatment (either medication or psychotherapy) for their depression. In addition, only 11 percent of the women were breastfeeding (which stimulates oxytocin production) six months after childbirth, compared to 42 percent of moms without depression.
Another positive that may come from the study is that researchers are looking into whether an oxytocin nasal spray could relieve PPD and depression in moms. Feldman and her colleagues are conducting a study among moms with PPD who have babies between 4 and 8 months old. She and her team are studying the effects of oxytocin nasal spray, combined with therapy, to help women interact positively with their babies "It makes sense that the combination of oxytocin medicine and therapy will work better than either one alone," Stuebe says.
If you think you may have postpartum depression, answer these simple screening questions.