Elevated brain monoamine oxidase A binding in the early postpartum period.
BACKGROUND
The early postpartum period is a time of high risk for a major depressive episode (or postpartum depression), with a prevalence of 13%. During this time, there is a heightened vulnerability for low mood because postpartum blues is common. Severe postpartum blues can herald the onset of postpartum depression. The neurobiological mechanisms to explain postpartum blues and the high risk for the onset of postpartum depression in the first few weeks after delivery are unclear. Estrogen levels drop 100- to 1000-fold during the first 3 to 4 days postpartum, and changes in estrogen levels have an inverse relationship with monoamine oxidase A (MAO-A) density. However, MAO-A levels have never been measured in the early postpartum period.


OBJECTIVE
To determine whether brain MAO-A binding is elevated in the early postpartum period.


METHODS
Case-control study.


METHODS
Tertiary care academic psychiatric hospital in Toronto, Ontario, Canada.


METHODS
Fifteen healthy women who were 4 to 6 days postpartum and 15 healthy women who had not recently been postpartum underwent carbon 11-labeled harmine positron emission tomography scanning. All women were nonsmoking and medication free.


METHODS
MAO-A total distribution volume, an index of MAO-A density, was measured in prefrontal cortex, anterior cingulate cortex, anterior temporal cortex, thalamus, dorsal putamen, hippocampus, and midbrain.


RESULTS
MAO-A total distribution volume was significantly elevated (mean, 43%) throughout all analyzed brain regions during the early postpartum period.


CONCLUSIONS
Elevated MAO-A levels in the early postpartum period can be interpreted as a marker of a monoamine-lowering process that contributes to the mood change of postpartum blues. Rather than a purely psychosocial model, we propose a neurobiological model of estrogen decline, followed by elevated MAO-A binding, low mood, and subsequently a period of high risk for major depressive episodes. Our model has important implications for preventing postpartum depression and for developing therapeutic strategies that target or compensate for elevated MAO-A levels during postpartum blues.
Sacher
Julia
J
Vivian M. Rakoff PET Centre, Centre for Addiction and Mental Health and Department of Psychiatry, University of Toronto, Toronto, Ontario M5T 1R8, Canada.
Wilson
Alan A
AA
Houle
Sylvain
S
Rusjan
Pablo
P
Hassan
Sabrina
S
Bloomfield
Peter M
PM
Stewart
Donna E
DE
Meyer
Jeffrey H
JH
D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000201:enzymology*; D002250:Carbon Radioisotopes; D016022:Case-Control Studies; D019052:Depression, Postpartum / Q000000981:diagnostic imaging / Q000201:enzymology*; D003865:Major Depressive Disorder / Q000000981:diagnostic imaging / Q000201:enzymology*; D004958:Estradiol / Q000378:metabolism; D005260:Female; D006247:Harmine; D006801:Humans; D008995:Monoamine Oxidase / Q000378:metabolism*; D049268:Positron-Emission Tomography; D012016:Reference Values
D002250:Carbon Radioisotopes; D006247:Harmine; D004958:Estradiol; D008995:Monoamine Oxidase