Preliminary evidence of reduced occipital GABA concentrations in puerperal women: a 1H-MRS study.
BACKGROUND
Childbirth is associated with rapid neuroendocrine fluctuations, which are thought to contribute to the phatogenesis of postpartum major depression (PPD).


OBJECTIVE
The aim of this proton magnetic resonance spectroscopy (1H-MRS) study was two-fold; 1) to examine whether puerperium is associated with alterations in occipital cortex gamma-aminobutyric acid (GABA) concentrations and 2) to determine whether such alterations may be more prominent in women with PPD.


METHODS
Nine women with PPD, 14 postpartum healthy controls, and ten healthy follicular phase females underwent 1H-MRS at 2.1 Tesla to measure occipital cortex GABA concentrations. Postpartum women were scanned within 6 months of delivery and prior to resumption of menstruation. Healthy non-puerperal controls, drawn from a historical sample, were scanned during the early to mid-follicular phase when ovarian hormone levels would be similar to those found in the puerperium. GABA data were analyzed using analysis of covariance, and regression models were used to explore the relationship between cortical GABA concentrations and blood levels of estradiol, progesterone, and neurosteroids.


RESULTS
Cortical GABA and plasma allopregnanolone (ALLO) concentrations were reduced in both groups of postpartum women, regardless of PPD diagnosis, compared to healthy follicular phase women. There was no correlation between cortical GABA concentrations and estradiol, progesterone, ALLO, or pregnenolone (PREG).


CONCLUSIONS
This study is the first to describe reductions in occipital cortex GABA levels in the postpartum period, a time of increased vulnerability to mood disturbances in women. The concomitant reduction in peripheral ALLO levels provides further evidence of alterations in the balance between cortical excitation and inhibition during the puerperium. Women with PPD may represent a subgroup of women who fail to adequately adapt to this alteration in the neuroendocrine milieu.
Epperson
C Neill
CN
Department of Psychiatry, Yale University School of Medicine, and Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT 06519, USA. neill.epperson@yale.edu
Gueorguieva
Ralitza
R
Czarkowski
Kathryn A
KA
Stiklus
Stephanie
S
Sellers
Edward
E
Krystal
John H
JH
Rothman
Douglas L
DL
Mason
Graeme F
GF
D000328:Adult; D019052:Depression, Postpartum / Q000378:metabolism*; D004958:Estradiol / Q000097:blood; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D009778:Occipital Lobe / Q000378:metabolism*; D049590:Postpartum Period / Q000378:metabolism*; D011278:Pregnanes / Q000097:blood; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D011278:Pregnanes; D004958:Estradiol; D005680:gamma-Aminobutyric Acid