monoamine model of postpartum blues. a: after delivery, estrogen levels drop 100- to 1000fold; the estrogen decline is greatest during the first 3 to 4 days postpartum, with a modest decline thereafter. b: monoamine oxidase a (mao-a) levels are significantly greater in the early postpartum period, with a peak on day 5 postpartum. c: in the early postpartum period, up to 70% of mothers experience sadness, mood lability, anxiety, insomnia, poor appetite, and irritability, with mood being lowest on day 5 postpartum.  credit: max planck institute for human cognitive and brain sciences