A review of 6 small trials found oxytocin may improve how postpartum mothers perceive their bond with their baby, but its effect on depressive mood is inconsistent — and one trial found it made depression worse.
1 out of 4 trials worsened moodWhile oxytocin improved depressive mood in one trial, another found it actually aggravated depression — highlighting that oxytocin is not a simple mood-booster
What the researchers found
Across 6 RCTs involving 195 women, oxytocin's effects on postpartum depression were mixed. For emotion: one trial showed oxytocin alleviated depressive mood, two showed no effect (though one found reduced negative thoughts in healthy mothers), and one actually showed oxytocin worsened depression. For cognition: four trials generally found oxytocin enhanced postpartum women's perception of their relationship with their infants. The review concluded that oxytocin may improve mother-infant cognitive bonding but its effects on depressive mood remain uncertain and contradictory.
Why it matters
Postpartum depression affects roughly 10-15% of new mothers and can severely impair mother-infant bonding and child development. Since oxytocin is naturally released during breastfeeding and skin-to-skin contact, it seemed like a logical therapeutic target. This review reveals a more nuanced reality: oxytocin may help mothers perceive their relationship with their baby more positively, but it doesn't reliably improve depressive mood — and in one case, actually worsened it.
The numbers in context
6 RCTs · 195 women total · 1 trial: improved mood · 2 trials: no mood effect · 1 trial: worsened depression · 4 trials: improved mother-infant cognitive perception
How the study worked
Systematic review of randomized controlled trials. Databases searched: PubMed, Web of Science, Cochrane Library, and EmBase from inception through April 2022. Six RCTs meeting inclusion criteria were analyzed qualitatively, with effects categorized into emotional outcomes and cognitive outcomes.
What this study cannot tell us
Very small total sample size (195 women across 6 studies). The review could not perform a meta-analysis due to heterogeneity in outcomes and measurements across studies. Different oxytocin doses, routes, and timing were used across trials. The finding that oxytocin worsened depression in one trial raises safety concerns that need further investigation. Only studies through April 2022 were included.
How to read the evidence
This is a systematic review of RCTs — a high-quality study design — but the evidence base is very limited (only 6 small trials, 195 women total). The conflicting results across studies prevent firm conclusions. The quality of evidence is low due to small sample sizes and heterogeneous methods.
When this study was published
Published in 2023 with searches through April 2022. The small number of existing trials (only 6) highlights how understudied this question remains despite oxytocin's popularity in public discourse.
The bigger picture
Oxytocin has been called the 'love hormone' and widely assumed to have broadly positive effects on social bonding and mood. This review adds to a growing body of evidence showing that exogenous oxytocin's effects are far more complex and context-dependent than the popular narrative suggests. In some social contexts, oxytocin can actually increase negative emotions. For postpartum depression specifically, the research base remains too small and contradictory to draw conclusions, leaving this as a hypothesis that hasn't been confirmed.
Questions still open
- Why did oxytocin worsen depression in one trial — does it amplify whatever emotional state the mother is already in?
- Could oxytocin's positive effects on mother-infant cognition improve long-term bonding outcomes even without directly treating depression?
- Are there subgroups of postpartum women (e.g., by oxytocin receptor genotype or baseline oxytocin levels) who would reliably benefit?
Common questions
Does oxytocin help with postpartum depression?
How could oxytocin make depression worse?
Read the original research
Oxytocin and Women Postpartum Depression: A Systematic Review of Randomized Controlled Trials.
Neuropsychiatric disease and treatment, 19, 939-947
Citation
Zhu, Jialei; Jin, Jing; Tang, Jing. (2023). Oxytocin and Women Postpartum Depression: A Systematic Review of Randomized Controlled Trials.. Neuropsychiatric disease and treatment, 19, 939-947. https://doi.org/10.2147/NDT.S393499