Psychedelic therapy and postpartum depression: priorities and prospects

Postpartum depression (PPD) affects about 15% of pregnant women globally and can disrupt maternal wellbeing, infant interaction and caregiving. The authors note that PPD overlaps with major depressive disorder but also reflects unique peripartum and postpartum changes in immune, neuroendocrine and neural systems. Although standard antidepressants remain widely used, their delayed onset can prolong distress, and the only drugs specifically approved for PPD are brexanolone and zuranolone. The introduction also highlights that early psychedelic studies in PPD are encouraging, but the benefit-risk balance is still uncertain, especially given the postpartum period’s physiological and caregiving demands. The purpose of this review is to examine whether serotonergic psychedelics could be relevant to PPD by bringing together evidence on immune, endocrine and neural pathways, and by considering how these drugs might influence maternal motivation, bonding and caregiving. The authors also aim to outline special considerations for delivering psychedelic therapy in the postpartum period and to identify priorities for future research. This is a narrative review rather than an original clinical trial. The authors position it as a synthesis intended to inform the rationale for psychedelic therapy in PPD and to identify gaps in the evidence base.

The authors conducted a PubMed search for English-language studies published between 2018 and 2025, while also considering earlier studies where relevant. Search terms covered immune, endocrine, neurophysiological, cognitive and neuroimaging topics, combined with keywords related to PPD. Titles and abstracts were screened by the authors to identify the most relevant reviews and articles. They excluded case reports, non-English articles, letters, opinion pieces, editorials, papers on vaccinations, pregnancy complications and diseases, and livestock-related articles. The review then organised the literature around endocrine pathways, the HPA axis, peptide hormones, neuroplasticity, immunomodulation and neural circuitry, with attention to how these systems may relate to maternal bonding and caregiving. No formal systematic review methods, study selection flow diagram, risk-of-bias assessment, or meta-analytic pooling are described in the extracted text. The paper therefore appears to be a narrative review grounded in targeted literature searching and thematic synthesis rather than a quantitative evidence synthesis.

The review summarises evidence that PPD is linked to dysregulation across several biological systems, although the findings are often heterogeneous. On endocrine pathways, the authors report that direct evidence on psychedelic effects on oestrogen and progesterone is lacking. They note only limited human evidence suggesting classic psychedelics may affect sex steroids indirectly, for example through interactions with aromatase and the HPA axis. For the GABA/neurosteroid system, the paper highlights that brexanolone and zuranolone support the idea that deficient GABAergic tone may be relevant in PPD, but direct studies of psychedelics on this system are sparse. Psilocybin and DOI have been shown in preclinical work to increase extracellular GABA in some brain regions, and ayahuasca has been reported to increase hippocampal GABA and decrease amygdala GABA in rats. The authors emphasise that firm conclusions cannot yet be drawn. On the HPA axis, the review reports that classic psychedelics acutely activate stress hormones. In animal studies, psilocybin and 5-MeO-DMT were associated with lower basal corticosterone or altered stress responses after the acute phase. In humans, psilocybin acutely increased plasma cortisol but did not significantly alter cortisol response to a later psychosocial stressor in a small study of 15 participants per group. Ayahuasca was associated with increased cortisol acutely and a more normalised cortisol awakening response 2 days later in patients with treatment-resistant depression. The authors interpret these findings as suggestive, but not sufficient, evidence that psychedelics might normalise stress-system function. For peptide hormones and maternal behaviour, the review reports that DOI, LSD and psilocybin can increase oxytocin and prolactin in preclinical and human studies, although MDMA appears to produce stronger oxytocin effects than LSD. Because reduced oxytocin is often reported in PPD and oxytocin is linked to reward-related maternal circuitry, the authors suggest that psychedelic-related changes in oxytocin signalling could be relevant to bonding and caregiving. They also cite animal work showing that classic psychedelics, ketamine and ibogaine can reopen a critical period for social reward learning, which may be mediated by oxytocin-dependent plasticity in the nucleus accumbens. In the neuroplasticity section, the paper summarises extensive preclinical evidence that psychedelics promote rapid and sustained structural plasticity. Mechanisms discussed include 5-HT2A receptor signalling, glutamate release, AMPA receptors, BDNF, TrkB and mTOR. The authors also note conflicting evidence about whether these effects can be separated from hallucinogenic effects, although genetic 5-HT2A receptor knockout studies are presented as supportive of a receptor role in antidepressant-like effects. Human measures of neuroplasticity are described as indirect and limited, and peripheral BDNF is considered an imperfect marker. The paper states that the relationship between these plasticity changes and PPD symptoms remains uncertain. In the immunomodulation section, the review reports that serotonergic psychedelics can alter immune activity in vitro, in animals and in humans. Some studies show reductions in pro-inflammatory cytokines and increases in anti-inflammatory markers, while others show the opposite or subtle effects depending on immune state and context. The authors also note emerging interest in the microbiota-gut-brain axis as a possible interface between psychedelics and inflammation, but state that more research is needed. For neural pathways, the review focuses on the default mode network and parental caregiving circuitry. It notes that PPD has been associated with altered activity in default mode network hubs and with reduced responsiveness in reward- and emotion-related regions such as the amygdala and ventral striatum. Psychedelics, particularly psilocybin and LSD, are described as decreasing within-network default mode connectivity, increasing global brain connectivity, and altering connectivity in regions involved in self-referential processing, reward and maternal behaviour. The authors argue that these effects could plausibly relate to reductions in rumination and improvements in emotional flexibility and bonding, but they present this as a hypothesis rather than established clinical fact. The paper also identifies practical considerations for postpartum psychedelic therapy, including the need for childcare arrangements, rigorous screening for postpartum psychosis risk, careful consent procedures, breastfeeding adaptations and potentially structured psychological or family-based support. The extracted text does not report new experimental results beyond the literature synthesis itself.

The authors conclude that psychedelic therapy is a promising prospect for PPD, but stress that the evidence base is still early and incomplete. They interpret the available preclinical and clinical findings as suggesting that psychedelic compounds may influence several systems relevant to PPD, including stress hormones, oxytocin-related bonding circuits, immune signalling and neuroplasticity. In their view, these multimodal effects make psychedelics plausible candidates for helping with symptoms such as rumination, maternal disconnection and disrupted caregiving. They place these ideas in the context of earlier research on MDD and treatment-resistant depression, while cautioning that findings from those populations cannot simply be transferred to PPD because postpartum patients face distinct hormonal, psychological and caregiving challenges. The authors emphasise that the existing PPD trials are preliminary and that evidence from related disorders should be extrapolated cautiously. Key limitations acknowledged in the discussion include the lack of a formal systematic review process, the incompleteness of the available literature and the fact that studies in PPD are still small and preliminary. They also note uncertainty about the best postpartum dosing window, the safety of repeated dosing, breastfeeding guidance, and whether planned psychotherapy should be integrated into treatment. The authors further highlight the need to identify subgroups most likely to benefit, potentially using immune, endocrine, neural and behavioural markers, as well as real-world data and long-term outcomes. For future work, they argue for larger, adequately powered trials with longer follow-up, better safety data, tailored safeguards for postpartum patients, and more integrated care pathways linking perinatal and adult mental health services. They also suggest that pragmatic regulatory frameworks, cost-effectiveness data and national registries may be needed if psychedelic therapy is to be responsibly incorporated into public health systems.

Psychedelic therapy may have potential for PPD, but the authors conclude that current evidence is only preliminary. They call for larger, well-powered clinical trials to establish safety, efficacy and optimal use in the postpartum period.