Postpartum depression (PPD) is a major health problem, and in recent years its prevalence has been increasing. The physiological changes and mood disorders associated with pregnancy and the postnatal period are mainly due to a hormonal imbalance. Destabilizing the mother's hypothalamic pituitary adrenal (HPA) axis increases the susceptibility to depression, probably by significantly increasing plasma cortisol. Stress and inflammation play a key role in postpartum. Also, lactogenic hormones have antidepressant and anxiolytic effects, the low concentration of oxytocin in the perinatal period being a triggering factor of PPD. Natural nutrition, ideal for every newborn and infant, positively influences the mother's mental health and may reduce the risk of developing PPD, possibly by attenuating cortisol response to stress. The link between breastfeeding and PPD has not been thoroughly approached. PPD is associated with early termination of breastfeeding, while long-term breastfeeding reduced the risk of PPD. The mother's willingness to breastfeed, her confidence in the ability to breastfeed, her mental health during pregnancy, her family's support, and trained medical staff are some of the mediators that can contribute to the maintenance of natural nutrition in PPD.