Heather Rupp, an Assistant Scientist with The Kinsey Institute for Research in Sex, Gender and Reproduction, has received a grant from NIMH (National Institute of Mental Health) for a study focusing on the mechanisms of Postpartum Depression.
Great, you say. But what exactly will she be studying?
“My colleagues and I will be investigating whether oxytocin, a hormone that reduces the physiological stress response and promotes social bonding, buffers new mothers against depression through its influences on their neural responsiveness to stress, and whether this process is disrupted in some way in women suffering from postpartum depression.”
Well that answers that. How will they be examining if this process is disrupted?
Using fMRI technology, Rupp and her colleagues will compare brain activity in the three groups in response to a series of images. Some of the women will also receive an oxytocin nasal spray.
Now for the who.
The study will involve three groups of women — new mothers who are not depressed, new mothers with PPD, and women who have never given birth.
Why bother examining all of this? What’s the hypothesis?
The prefrontal-limbic system is a part of the brain that may be involved in maternal behavior. New mothers generally show changes in the responsiveness of the prefrontal-limbic system to infants in ways that differ from women who have not just given birth. New mothers may also show less sensitivity to stress. Additionally, women who suffer depression outside of the postpartum period show heightened responsiveness of the prefrontal-limbic system in response to stress, suggesting an overlap in circuits critical to maternal behavior and those altered by depression. It is unknown whether changes in this prefrontal limbic system are related to postpartum depression (PPD).
The mechanism for altered neural responsiveness in the postpartum period may involve oxytocin, which also occurs at higher levels in new mothers. It is hypothesized that this makes the new mother less affected, generally, by negative stressors from the outside world, but more responsive to her infant.
But wouldn’t the oxytocin levels be different when comparing breastfeeding vs. bottle feeding moms? Will that relationship dynamic be examined during this study?
I had this very question when I first read the study and immediately emailed Heather to ask if this would be included. Her response?
It is a great question- you would expect differences in oxytocin, neural responsiveness to stress, and prevalence of depression in breast versus bottle feeding women.
Initially this comparison was part of the study design. This turned out to be just too complicated for one study, however.
Comparing so many groups of women would be beyond the scope of the funding we received. So we cut out the bottle-feeding women in this initial study. Based on what we learn from the upcoming study, we hope to then follow-up with questions such as bottle versus breast feeding moms.
Any of the above information in quotes (with exception of the breastfeeding comment which was via email with Heather Rupp) was taken directly from a press release from Indiana University which can be accessed by clicking here.