Oxytocin selectively enhances the recognition of infant sadness in postpartum depression

BackgroundLittle is known about the role of oxytocin in the processing of positive emotional infant cues in mothers with PPD.ObjectivesWe therefore examined whether intranasal oxytocin influences postpartum mothers' processing of positive infant emotional cues, both visual (facial expressions) and auditory (laughter), and intended caregiving responses.DesignThis double-blind randomized controlled crossover study included 45 mothers, with 3- to 9-month-old infants, who exhibited clinically relevant scores on the Edinburgh Postnatal Depression Scale, with 35 mothers fulfilling the criteria of a major depressive episode assessed with the SCID-5.MethodsMothers participated in two randomized counterbalanced sessions, receiving oxytocin and placebo in separate sessions with a washout period in between. During both sessions they completed an infant facial emotion recognition (FER) task and listened to infant laughter while physiological and self-report measures were collected.ResultsWe found that oxytocin shifted response bias away from fear and toward sadness, while increasing accuracy for sad infant faces. This pattern suggests that oxytocin selectively reallocates attention from threat-related cues to those signaling infant need. Additionally, oxytocin elevated heart rate in response to infant laughter, indicating greater physiological engagement with positive cues, although self-reported affect and caregiving intentions were unaffected.ConclusionsThese findings suggest that oxytocin may fine-tune perceptual and physiological responsiveness to emotionally salient infant signals rather than uniformly enhancing positive emotion recognition. The adaptive implications of this shift remain mixed: enhanced sensitivity to sadness may facilitate caregiving, yet excessive focus on distress could increase negative affect in vulnerable mothers. Oxytocin's effects thus appear emotion-specific, potentially providing mechanistic insight into altered maternal perception in postpartum depression. Future work should examine real-world caregiving behaviors and individual moderators, such as depression severity and trauma history, to clarify oxytocin's potential therapeutic relevance. Registration: The study is registered at the European Clinical Trial Registry.