Breastfeeding and Postpartum Depression: What's the Link?

How do the hormones of breastfeeding affect mood?

Two hormones released during nursing — oxytocin and prolactin — are associated with calming and bonding effects:

• Oxytocin is released with each letdown and promotes relaxation, trust, and connection while lowering short-term cortisol (the stress hormone).
• Prolactin, which drives milk production, has a mild sedative, calming quality described in the physiological literature on lactation 3Ref 3World Health Organization (2009).Infant and Young Child Feeding: Model Chapter — Session 2: The Physiological Basis of Breastfeeding.Physiological roles of oxytocin and prolactin in breastfeeding, including mood and calming effects and hormonal changes during weaning.

For people who breastfeed without significant difficulty, these hormonal effects may support mood stability in the postpartum period. A 2022 systematic review and meta-analysis found that women who did not exclusively breastfeed had 89% higher odds of postpartum depression compared to those who did (OR = 1.89) 1Ref 1Alimi R, Azmoude E, Moradi M, Zamani M (2022).The Association of Breastfeeding with a Reduced Risk of Postpartum Depression: A Systematic Review and Meta-Analysis.Women who did not exclusively breastfeed had 89% higher odds of postpartum depression (OR 1.89, 95% CI 1.50–2.39); exclusive breastfeeding is associated with reduced PPD risk. However, the direction of causality is complex: people who are already doing well may be more likely to breastfeed successfully in the first place.

Can breastfeeding difficulties worsen postpartum mental health?

Yes, and this is clinically important to acknowledge. Breastfeeding problems — pain, poor latch, low supply, engorgement, mastitis — are significant sources of distress in the early postpartum weeks. Sleep deprivation from frequent nursing amplifies this further.

Research has found that difficulty meeting breastfeeding goals is associated with increased rates of postpartum depression 2Ref 2American College of Obstetricians and Gynecologists (2018).ACOG Committee Opinion No. 756: Optimizing Support for Breastfeeding as Part of Obstetric Practice.ACOG guidance on postpartum depression screening, treatment compatibility with breastfeeding, and shared decision-making for feeding goals. The relationship is bidirectional: depression can interfere with breastfeeding, and breastfeeding struggles can worsen depression. When someone is in pain, sleep-deprived, and worried their baby is not getting enough nutrition, mental health suffers.

This means that supporting a person to either breastfeed more successfully — or to make a guilt-free transition to formula, whichever reduces their distress — can be equally protective of their mental health.

What is dysphoric milk ejection reflex (D-MER)?

D-MER is a distinct physiological condition in which some breastfeeding people experience a sudden wave of negative emotion — sadness, anxiety, dread, or irritability — occurring in the moments just before or during milk letdown, resolving within one to two minutes after milk starts flowing.

This is not postpartum depression. Research suggests it is related to an abrupt drop in dopamine that normally precedes the prolactin surge at letdown 4Ref 4Deif R, Burch EM, Azar J, Yonis N, Abou Gabal M, El Kramani N, DakhlAllah D (2021).Dysphoric Milk Ejection Reflex: The Psychoneurobiology of the Breastfeeding Experience.D-MER mechanism: abrupt dopamine drop at letdown triggering transient dysphoria, distinct from postpartum depression. People with D-MER often describe the feelings as coming “out of nowhere” and not matching their overall emotional state.

D-MER is real, recognized, and not a character flaw. Awareness is the first step — many people feel profound relief when they learn there is a name for what they experience. A lactation consultant or behavioral health provider can discuss management options.

What if I have postpartum depression and I am breastfeeding?

Postpartum depression is common, affecting roughly 1 in 5 new mothers, and it is a medical condition that requires treatment 2Ref 2American College of Obstetricians and Gynecologists (2018).ACOG Committee Opinion No. 756: Optimizing Support for Breastfeeding as Part of Obstetric Practice.ACOG guidance on postpartum depression screening, treatment compatibility with breastfeeding, and shared decision-making for feeding goals. It does not resolve reliably without support.

If you are experiencing persistent sadness, anxiety, loss of pleasure, difficulty bonding with your baby, or thoughts of harming yourself or your baby, please reach out to a clinician. Both counseling (particularly cognitive behavioral therapy) and medications are effective 2Ref 2American College of Obstetricians and Gynecologists (2018).ACOG Committee Opinion No. 756: Optimizing Support for Breastfeeding as Part of Obstetric Practice.ACOG guidance on postpartum depression screening, treatment compatibility with breastfeeding, and shared decision-making for feeding goals.

Many medications used to treat postpartum depression are compatible with breastfeeding. The ACOG Committee Opinion on breastfeeding support emphasizes that obstetric providers should help mothers navigate both treatment and feeding goals together 2Ref 2American College of Obstetricians and Gynecologists (2018).ACOG Committee Opinion No. 756: Optimizing Support for Breastfeeding as Part of Obstetric Practice.ACOG guidance on postpartum depression screening, treatment compatibility with breastfeeding, and shared decision-making for feeding goals. The right answer for most families is: treat the depression, continue breastfeeding if it is possible and desired, and get help from both sides.

Can stopping breastfeeding cause depression?

Some people notice a dip in mood when weaning, particularly if it is abrupt. The drop in prolactin and oxytocin as breastfeeding ends can affect the hormonal landscape, though most people adjust without lasting difficulty 3Ref 3World Health Organization (2009).Infant and Young Child Feeding: Model Chapter — Session 2: The Physiological Basis of Breastfeeding.Physiological roles of oxytocin and prolactin in breastfeeding, including mood and calming effects and hormonal changes during weaning.

If you are weaning and notice significant mood changes, it is worth mentioning to your clinician. This is especially true if you have a history of depression or experienced mood changes at other times of hormonal shift (such as premenstrually or with hormonal contraception).

Weaning gradually rather than abruptly, when circumstances allow, gives the body more time to adjust hormonally and may reduce the severity of any mood changes.