Your Subtitle text
Mechanism of D-MER
The Mechanism of Dysphoric Milk Ejection Reflex:
What Causes It

D-MER has been linked to an inappropriate drop in dopamine that occurs whenever milk is released. In a mother with D-MER at the time of letdown dopamine falls inappropriately, causing negative feelings. All of the suggestions made for treating D-MER are based on the belief that
transiently inadequate dopamine is responsible.

Milk release itself isn't caused by dopamine dropping; it's caused by oxytocin rising. In D-MER, the MER (milk ejection reflex) is a result of rising oxytocin (needed to move the milk out of the breast) but the D (dysphoria) is a result of inappropriately falling dopamine. Dopamine gets involved because it inhibits prolactin (which is what makes the milk) so dopamine levels need to drop for prolactin levels to rise in order to make more milk. Normally, dopamine drops properly and breastfeeding mothers never knew it even happened, in D-MER mothers however, it doesn't drop properly and causes an instant and brief wave of  a negative emotional reaction that lasts until the dopamine levels restabilize after prolactin has begun it's rise. 

D-MER follows the 
same pattern as any other reflex. You can tell yourself your knee isn't going to jerk when you hit it... but it does, just as much the hundredth time as it does the first, and it stops as soon as the stimulus stops. The D-MER reflex involves e-motion rather than motion because a hormone shift is triggered instead of having a muscle nerve triggered. D-MER is physiological, not psychological. It is hormones, not past experience or repressed memories, that cause it.