THURSDAY, Sept. 16 (HealthDay News) -- Women with postpartum
depression have differences in brain functioning that may interfere
not only with how they process their own emotions, but also with
their ability to be responsive to the emotions of their infants,
new research suggests.
In a small study that involved MRI brain scans, researchers at
the University of Pittsburgh Medical Center revealed that women
with postpartum depression have reduced activity in parts of the
brain that control emotional responses and recognize emotional cues
"Our study provides a brain basis for what has been described in clinical settings and behavioral studies, which is that women with postpartum depression may have reduced activity in regions of the brain that process emotions and that are involved in being attuned to others' emotions," said study author Dr. Eydie L. Moses-Kolko, an assistant professor of psychiatry at the University of Pittsburgh School of Medicine. These brain abnormalities may help explain why mothers with postpartum depression often have problems bonding with their infants, she noted.
Postpartum depression, which affects an estimated 15 percent of
new moms, is different than the typical "baby blues" that often
occur after delivery, when a new mother may burst into tears at the
drop of a hat, experts said.
While the baby blues usually go away within two weeks of giving
birth, postpartum depression can continue for months and often
causes such strong feelings of sadness, anxiety or despair that a
woman has trouble coping with her daily tasks. Previous research
has shown that maternal depression can negatively affect an
infant's mental and physical development.
Moses-Kolko and her colleagues studied 14 depressed and 16
healthy mothers, all of whom delivered a healthy term infant in the
preceding 12 weeks, were medication-free and had previously given
birth to another child. The mothers were shown images of angry and
scared faces, and the researchers examined their neural reactions
to the pictures with the use of MRI scans. The mothers also filled
out questionnaires that assessed their attachment quality,
hostility and pleasure in interaction with their infants.
The researchers found that negative emotional faces activated
the left dorsomedial prefrontal cortex, which is a social cognition
region of the brain, significantly less in depressed mothers than
in healthy mothers. Deficits in this region, they said, might
represent diminished awareness of the emotions of others and less
empathy for them. Another key finding was that when the women saw
negative images, communication between the left dorsomedial
prefrontal cortex and the left amygdala was present in healthy moms
but not in the depressed ones, suggesting that this might be an
important neural circuit that regulates emotional response to
unpleasant sounds, such as a baby's cry.
The study, which was partly funded by the U.S. National
Institute of Mental Health and the National Alliance for Research
on Schizophrenia and Depression, was published Sept. 15 in the
online advance edition of the
American Journal of Psychiatry.
Moses-Kolko said more research is needed "to determine what
brain patterns are predictive of response to an array of treatments
including psychotherapy, medications or hormones."
"This is a very interesting study, but it's really just the beginning," said Michael W. O'Hara, a professor of psychology at the University of Iowa in Iowa City, who specializes in perinatal depression. "More studies need to be done in a much larger sample of women, to see if the results can be replicated."
O'Hara added: "It's my belief that postpartum depression is a
heterogeneous disorder that includes depression that is
coincidental with childbirth, and depression that is inextricably
related to it." Future MRI studies need to differentiate between
these two groups of women, he said, because "if we mix these two
samples together, it may obscure the true findings."
For more on postpartum depression, visit the
U.S. National Library of Medicine.