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Background: Postpartum depression (PPD) constitutes a significant mental health disorder affecting almost one fifth of pregnancies globally. Despite extensive research, the precise etiological mechanisms underlying PPD remain elusive. However, several risk factors like genetic predisposition, hormonal fluctuations, and stress-related environmental and psychosocial triggers have been found to be implicated in its development. MAIN: Recently, an increased risk of PPD has been reported to be associated with gestational diabetes mellitus (GDM), which is characterized by the disruption of glucose metabolism, primarily attributed to the emergence of insulin resistance (IR). While IR during pregnancy seems to be an evolutionary adaptative mechanism to handle the profound metabolic alterations during pregnancy, its subsequent resolution following delivery necessitates a reconfiguration of the metabolic landscape in both peripheral tissues and the central nervous system (CNS). Considering the pivotal roles of energy metabolism, particularly glucose metabolism, in CNS functions, we propose a novel model that such pronounced changes in IR and the associated glucose metabolism seen postpartum might account for PPD development. This concept is based on the profound influences from insulin and glucose metabolism on brain functions, potentially via modulating neurotransmitter actions of dopamine and serotonin. Their sudden postpartum disruption is likely to be linked to mood changes, as observed in PPD., Conclusions: The detailed pathogenesis of PPD might be multifactorial and still remains to be fully elucidated. Nevertheless, our hypothesis might account in part for an additional etiological factor to PPD development. If our concept is validated, it can provide guidance for future PPD prevention, diagnosis, and intervention., (© 2024. The Author(s).)

Postpartum depression and depressive symptoms have a major impact on maternal and infant health and well-being, yet to date their aetiology remains unclear. One hypothesis suggests a link between these symptoms and variations in prenatal cortisol levels, but existing evidence is limited and inconclusive. This study aims to provide additional evidence to disentangle the relationship between prenatal cortisol concentrations and subsequent occurrence of postpartum depressive symptoms. Cortisol for all three trimesters of pregnancy was extracted from the hair of 775 women participating in the French ELFE cohort. Depressive symptomatology at two months postpartum was assessed through the Edinburgh Postpartum Depression Scale (EPDS). Associations between prenatal cortisol levels and EPDS scores were tested using propensity-score weighted logistic regression models to control for confounders. An increase in mean cortisol concentrations was observed from the first to the third trimester of pregnancy. No significant differences in hair cortisol concentrations were found during the first and second trimesters between women who experienced postpartum depressive symptoms and those who did not. However, an association was observed between third trimester hair cortisol concentrations and depressive symptoms at two months postpartum. Women whose cortisol concentrations fell within the second quartile had a higher risk of subsequent PPDS (aOR = 2.67, 95%CI [1.01, 7.08]). Using a large sample from the general population, we observed an association between hair cortisol levels during the third trimester of pregnancy and postpartum depressive symptoms. Nevertheless, our results suggest that future studies could benefit from investigating other biomarkers of the reactivity of the corticotropic axis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Despite the increase in the prevalence of postpartum depression among maternal disorder, its treatment outcomes remain suboptimal. Studies have shown that exercise can reduce postpartum depressive episodes in the mother, but the effects of exercise during pregnancy on maternal behavior and the potential mechanisms involved remain poorly understood. From the second day of pregnancy to the day of birth, dams exercised for 1 h a day by running on a controlled wheel. The maternal behaviors of the dams were assessed on postpartum day 2 to postpartum day 8. Chronic restraint stress was applied from postpartum day 2 to day 12. Blood was collected on postpartum days 3 and 8, then subjected to ELISA to determine the serum concentration of prolactin. The weight of each dam and the food intake were recorded. Anxiety- and depression-like behavioral tests were conducted, and hippocampal neuroinflammation and prolactin receptor levels were measured. The dams exhibited elevated levels of anxiety and depression, decreased serum prolactin levels, decreased prolactin receptor expression, and activation of NLRP3-mediated neuroinflammation in the hippocampus following the induction of postpartum chronic restraint stress, which were reversed with controlled wheel running during pregnancy. Overall, the findings of this study revealed that the preventive effects of exercise during pregnancy on postpartum anxiety-and depression-like behaviors were accompanied by increased serum prolactin levels, hippocampal prolactin receptor expression and hippocampal NLRP3-mediated neuroinflammation., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Postpartum depression (PPD) is a serious psychiatric disorder that has significantly adverse impacts on maternal health. Metabolic abnormalities in the brain are associated with numerous neurological disorders, yet the specific metabolic signaling pathways and brain regions involved in PPD remain unelucidated., Methods: We performed behavioral test in the virgin and postpartum mice. We used mass spectrometry imaging (MSI) and targeted metabolomics analyses to investigate the metabolic alternation in the brain of GABA A R Delta-subunit-deficient (Gabrd -/- ) postpartum mice, a specific preclinical animal model of PPD. Next, we performed mechanism studies including qPCR, Western blot, immunofluorescence staining, electron microscopy and primary astrocyte culture. In the specific knockdown and rescue experiments, we injected the adeno-associated virus into the central amygdala (CeA) of female mice., Results: We identified that prostaglandin D2 (PGD2) downregulation in the CeA was the most outstanding alternation in PPD, and then validated that lipocalin-type prostaglandin D synthase (L-PGDS)/PGD2 downregulation plays a causal role in depressive behaviors derived from PPD in both wild-type and Gabrd -/- mice. Furthermore, we verified that L-PGDS/PGD2 signaling dysfunction-induced astrocytes atrophy is mediated by Src phosphorylation both in vitro and in vivo., Limitations: L-PGDS/PGD2 signaling dysfunction may be only responsible for the depressive behavior rather than maternal behaviors in the PPD, and it remains to be seen whether this mechanism is applicable to all depression types., Conclusion: Our study identified abnormalities in the L-PGDS/PGD2 signaling in the CeA, which inhibited Src phosphorylation and induced astrocyte atrophy, ultimately resulting in the development of PPD in mice., Competing Interests: Declaration of competing interest The authors report no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Postpartum depression (PPD) affects 174 million women worldwide and is characterized by profound sadness, anxiety, irritability, and debilitating fatigue, which disrupt maternal caregiving and the mother-infant relationship. Limited pharmacological interventions are currently available. Our understanding of the neurobiological pathophysiology of PPD remains incomplete, potentially hindering the development of novel treatment strategies. Recent hypotheses suggest that PPD is driven by a complex interplay of hormonal changes, neurotransmitter imbalances, inflammation, genetic factors, psychosocial stressors, and hypothalamic-pituitary-adrenal (HPA) axis dysregulation. This narrative review examines recent clinical studies on PPD within the past 15 years, emphasizing advancements in neuroimaging findings and blood biomarker detection. Additionally, we summarize recent laboratory work using animal models to mimic PPD, focusing on hormone withdrawal, HPA axis dysfunction, and perinatal stress theories. We also revisit neurobiological results from several brain regions associated with negative emotions, such as the amygdala, prefrontal cortex, hippocampus, and striatum. These insights aim to improve our understanding of PPD's neurobiological mechanisms, guiding future research for better early detection, prevention, and personalized treatment strategies for women affected by PPD and their families.

Hypothalamic neural circuits regulate instinctive behaviors such as food seeking, the fight/flight response, socialization, and maternal care. Here, we identified microdeletions on chromosome Xq23 disrupting the brain-expressed transient receptor potential (TRP) channel 5 (TRPC5). This family of channels detects sensory stimuli and converts them into electrical signals interpretable by the brain. Male TRPC5 deletion carriers exhibited food seeking, obesity, anxiety, and autism, which were recapitulated in knockin male mice harboring a human loss-of-function TRPC5 mutation. Women carrying TRPC5 deletions had severe postpartum depression. As mothers, female knockin mice exhibited anhedonia and depression-like behavior with impaired care of offspring. Deletion of Trpc5 from oxytocin neurons in the hypothalamic paraventricular nucleus caused obesity in both sexes and postpartum depressive behavior in females, while Trpc5 overexpression in oxytocin neurons in knock-in mice reversed these phenotypes. We demonstrate that TRPC5 plays a pivotal role in mediating innate human behaviors fundamental to survival, including food seeking and maternal care., Competing Interests: Declaration of interests I.S.F. has consulted for a number of companies developing weight loss drugs (including Eli Lilly, Novo Nordisk, and Rhythm Pharmaceuticals) and investors (Goldman Sachs, SV Health). I.S.F. is a member of the Advisory Board of Cell. J.R.B.P. is an employee and shareholder of Insmed, receives research funding from GSK, and is a paid consultant for WW International. K.W.W. holds shares in Novo Nordisk and Eli Lilly., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Allopregnanolone (ALLO) is a metabolite of progesterone and a neuroactive steroid hormone. As a positive allosteric modulator of gamma-aminobutyric acid (GABA) receptors, ALLO seems to have antidepressant and anxiolytic effects, and was therefore approved as a specific medication for the treatment of postpartum depression in 2019. Despite the growing number of publications investigating ALLO levels, results on the biological and psychological correlates in the peripartum period remain inconsistent, possibly due to methodological challenges regarding measurement. To date, however, there is no systematic review examining the correlates, concentrations, and challenges in measuring ALLO in peripartum women., Method: A systematic literature search of PubMed and PsycINFO was conducted in August 2023. Original research articles that measured ALLO concentrations in peripartum women were included. Reports were excluded if they were not original research, included non-human subjects, did not include peripartum women, did not include ALLO measurement as an outcome, included (pharmacological) interventions, constituted method validations, or used the same cohort as another study., Results: The literature search yielded 234 articles, and two articles were identified from other sources. After full-text screening, 19 articles (N = 1401) met the inclusion criteria, of which seven focused on biological correlates of ALLO and 12 on mood correlates. Of the latter, six found no association between ALLO and mood, four found a negative association, and two found a positive association. Overall, the results show an increase in ALLO levels during pregnancy and a decrease after birth, with levels then remaining low until six months postpartum. ALLO was most commonly measured in blood plasma and by gas chromatography-mass spectrometry (GC-MS). A significant matrix effect was found for blood serum and a significant method effect for radioimmunoassays (RIAs). A significant effect of time of measurement was found., Conclusion: ALLO measurement shows method and matrix effects. ALLO levels are higher when measured in serum compared to in plasma, and when measured using RIA compared to other methods. Time of measurement, study design, and standardization of measurement also influence the reliability of measurement and the interpretation of results., Competing Interests: Declaration of Competing Interest The authors have no competing interests to declare. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Postpartum depression (PPD) is a severe mental disorder that affects approximately 10---20% of women after childbirth. The precise mechanism underlying PPD pathogenesis remains elusive, thus limiting the development of therapeutics. Gut microbiota dysbiosis is considered to contribute to major depressive disorder. However, the associations between gut microbiota and PPD remain unanswered. Here, we established a mouse PPD model by sudden ovarian steroid withdrawal after hormone-simulated pseudopregnancy-human (HSP-H) in ovariectomy (OVX) mouse. Ovarian hormone withdrawal induced depression-like and anxiety-like behaviors and an altered gut microbiota composition. Fecal microbiota transplantation (FMT) from PPD mice to antibiotic cocktail-treated mice induced depression-like and anxiety-like behaviors and neuropathological changes in the hippocampus of the recipient mice. FMT from healthy mice to PPD mice attenuated the depression-like and anxiety-like behaviors as well as the inflammation mediated by the NOD-like receptor protein (NLRP)-3/caspase-1 signaling pathway both in the gut and the hippocampus, increased fecal short-chain fatty acids (SCFAs) levels and alleviated gut dysbiosis with increased SCFA-producing bacteria and reduced Akkermansia in the PPD mice. Also, downregulation of NLRP3 in the hippocampus mitigated depression-like behaviors in PPD mice and overexpression of NLRP3 in the hippocampal dentate gyrus induced depression-like behaviors in naïve female mice. Intriguingly, FMT from healthy mice failed to alleviate depression-like behaviors in PPD mice with NLRP3 overexpression in the hippocampus. Our results highlighted the NLRP3 inflammasome as a key component within the microbiota-gut-brain axis, suggesting that targeting the gut microbiota may be a therapeutic strategy for PPD., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Postpartum depression (PPD) is a serious mental health problem that can negatively affect future generations. BDNF/AKT/mTOR signaling in the frontal lobe and hippocampus in mice is associated with depression, but its role in mice with PPD and their offspring is unknown. This study was aimed at investigating the effects of esketamine (ESK), a drug approved for treatment of refractory depression, on the BDNF/AKT/mTOR pathway in mice with PPD and their offspring. A model of chronic unpredictable mild stress with pregnancy was used. ESK was injected into postpartum mice, and behavioral tests were conducted to predict the severity of symptoms at the end of lactation and in the offspring after adulthood. Both mice with PPD and their offspring showed significant anxiety- and depression-like behaviors that were ameliorated with the ESK intervention. ESK enhanced exploratory behavior in unfamiliar environments, increased the preference for sucrose, and ameliorated the impaired BDNF/AKT/mTOR signaling in the frontal and hippocampal regions in mice. Thus, ESK may have great potential in treating PPD and decreasing the incidence of depression in offspring., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Purpose: Women are at high risk of stress, anxiety, and depression during the postpartum but the ways in which these different types of psychological distress are related to cortisol regulation is not clear. We examined the distinct association of each type of distress with women's average cortisol level, cortisol awakening response (CAR), cortisol decline across the day (diurnal slope), and overall amount of cortisol secretion across the day (AUC G )., Methods: At 6 months postpartum, a diverse group of 58 women completed measures of depression, anxiety, perceived stress, and life stressors. Each woman provided 4 salivary samples for cortisol assay from waking to bedtime on each of 2 consecutive days. Linear regressions were used to examine associations of stress, anxiety and depression to each of the 4 cortisol measures, controlling for number of stressful life events., Results: Depressive symptoms were associated with less of a rise in the CAR (β = -.46, p = 0.01), steeper diurnal slope (β = .51, p = 0.006), and higher average cortisol level (β = .42, p = .01). Women who met the clinical cutoff for an anxiety disorder had lower overall cortisol output (β = -.29, p = 0.03). Stress was not related to any cortisol metric., Conclusions: Findings suggest that stress is less associated with cortisol alterations in the postpartum than are more severe types of psychological distress. Anxiety and depression may have distinct and opposite profiles of cortisol dysregulation. Results indicate that mental health assessment is critical even in the later postpartum so that interventions can be initiated to reduce emotional suffering and the risk of impaired cortisol regulation., (© 2024. The Author(s).)

The absence of non-invasive tests that can monitor the status of the brain is a major obstacle for psychiatric care. In order to address this need, we assessed the feasibility of using tissue-specific gene expression to determine the origin of extracellular vesicle (EV) mRNAs in peripheral blood. Using the placenta as a model, we discovered that 26 messenger RNAs that are specifically expressed in the placenta are present in EVs circulating in maternal blood. Twenty-three of these transcripts were either exclusively or highly expressed in maternal blood during pregnancy only and not in the postpartum period, verifying the feasibility of using tissue-specific gene expression to infer the tissue of origin for EV mRNAs. Using the same bioinformatic approach, which provides better specificity than isolating L1 cell-adhesion molecule containing EVs, we discovered that 181 mRNAs that are specifically expressed in the female brain are also present in EVs circulating in maternal blood. Gene set enrichment analysis revealed that these transcripts, which are involved in synaptic functions and myelination, are enriched for genes implicated in mood disorders, schizophrenia, and substance use disorders. The EV mRNA levels of 13 of these female brain-specific transcripts are associated with postpartum depression (adjusted p-vals = 3 × 10 -5 to 0.08), raising the possibility that they can be used to infer the state of the brain. In order to determine the extent to which EV mRNAs reflect transcription in the brain, we compared mRNAs isolated from cells and EVs in an iPSC-derived brain microphysiological system differentiated for 3 and 9 weeks. We discovered that, although cellular and extracellular mRNA levels are not identical, they do correlate, and it is possible to extrapolate cellular RNA expression changes in the brain via EV mRNA levels. Our findings bring EV mRNAs to the forefront of peripheral biomarker development efforts in psychiatric diseases by demonstrating the feasibility of inferring transcriptional changes in the brain via blood EV mRNA levels., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Aims: To assess the effect of the translocator protein 18 kDa (TSPO) on postpartum depression and explore its mechanism., Methods: Postpartum depression (PPD) mouse model was established, and flow cytometry, immunofluorescence, Western blot analysis, real-time quantitative PCR, adeno-associated virus (AAV), co-immunoprecipitation-mass spectrometry and immunofluorescence co-staining were used to detect the effect of TSPO ligand ZBD-2 on PPD mice., Results: ZBD-2 inhibits the overactivation of microglia in the hippocampus and amygdala of PPD model mice. ZBD-2 not only inhibited the inflammation but also repressed the burst of reactive oxygen species (ROS) and mitochondrial ROS (mtROS). Meanwhile, ZBD-2 protects mitochondria from LPS-induced damages through inhibiting the influx of calcium. ZBD-2 modulated the calcium influx by increasing the level of translocase of the outer mitochondrial membrane 40 (TOM40) and reducing the interaction of TSPO and TOM40. In addition, the effect of ZBD-2 was partially dependent on anti-oxidative process. Knockdown of TOM40 by adeno-associated virus (AAV) in the hippocampus or amygdala dramatically reduced the effect of ZBD-2 on PPD, indicating that TOM40 mediates the effect of ZBD-2 on PPD., Conclusions: TOM40 is required for the effect of ZBD-2 on treating anxiety and depression in PPD mice. This study reveals the role of microglia TSPO in PPD development and provides the new therapeutic strategy for PPD., Competing Interests: Declaration of competing interest The authors have nothing to disclose and declare no conflicts of interest., (Copyright © 2023. Published by Elsevier B.V.)

Postpartum depression (PPD) is a leading cause of morbidity and mortality among women. Clinically, the administration and withdrawal of supraphysiologic estradiol and progesterone (E2 + P) can cause affective symptom reoccurrence in women with a history of PPD, but not matched controls. To investigate the cellular basis underlying this differential affective response, lymphoblastoid cell lines (LCLs) were derived from women with and without past PPD and compared transcriptomically in hormone conditions mimicking pregnancy and parturition: supraphysiologic E2 + P-addback; supraphysiologic E2 + P-withdrawal; and no added E2 + P (Baseline). RNA-sequencing identified unique differentially expressed genes (DEGs) in all hormone conditions, but the majority tended to be downregulated in PPD and observed in E2 + P-addback. Two of these DEGs were evolutionarily conserved cellular stress regulators: IMPACT, an integrative response protein maintaining translational homeostasis, and WWTR1, a transcriptional coactivator in the 'Hippo' pathway mediating cell proliferation and survival. Correspondingly, significant gene network modules were linked to cell cycle progression, estrogen response, and immune dysregulation, suggesting innate differences in intracellular signaling in PPD. In certain hormone conditions, PPD LCLs displayed increased GATA3 expression (an upstream regulator of IMPACT and WWTR1) and differentially phosphorylated eiF2α (the ultimate downstream target of IMPACT). Taken together, these transcriptomic data primarily implicate innately dysregulated cellular responses as potentially influencing mood and/or escalating PPD risk. Furthermore, the intrinsic downregulation of IMPACT's translation and WWTR1's transcription networks may suggest a novel link between PPD and a compromised ability to maintain homeostasis in the context of cellular stress occurring during pregnancy and parturition., (© 2023. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Brexanolone, a formulation of the neurosteroid allopregnanolone (ALLO), is approved for treating postpartum depression (PPD) and is being investigated for therapeutic efficacy across numerous neuropsychiatric disorders. Given ALLO's beneficial effects on mood in women with PPD compared to healthy control women, we sought to characterize and compare the cellular response to ALLO in women with ( n = 9) or without ( n = 10, i.e., Controls) past PPD, utilizing our previously established patient-derived lymphoblastoid cell lines (LCLs). To mimic in vivo PPD ALLO-treatment, LCLs were exposed to ALLO or DMSO vehicle for 60 h and RNA-sequenced to detect differentially expressed genes (DEGs, p nominal < 0.05). Between ALLO-treated Control and PPD LCLs, 269 DEGs were identified, including Glutamate Decarboxylase 1 ( GAD1 ), which was decreased 2-fold in PPD. Network analysis of PPD:ALLO DEGs revealed enriched terms related to synaptic activity and cholesterol biosynthesis. Within-diagnosis analyses (i.e., DMSO vs. ALLO) detected 265 ALLO-induced DEGs in Control LCLs compared to only 98 within PPD LCLs, with just 11 DEGs overlapping. Likewise, the gene ontologies underlying ALLO-induced DEGs in PPD and Control LCLs were divergent. These data suggest that ALLO may activate unique and opposing molecular pathways in women with PPD, which may be tied to its antidepressant mechanism.

Background: Postpartum depression (PPD) causes maternal mortality, and has a high disability rate. In recent years, studies have suggested the Sirt1 gene to be involved in the pathogenesis of depression. Resveratrol (RSV), an activator of Sirt1, has been investigated in depressive behavior. However, its effect on PPD remains to be thoroughly elucidated., Methods: We employed a mice model with bilateral oophorectomy combined with hormone-simulated pregnancy to assess postpartum depression-like behavior. The behavioral tests were performed 2 days after the withdrawal of estradiol benzoate. RSV was administered subcutaneously to the PPD model mice. Several behavioral tests were executed, including the open field test, forced swimming test, and tail suspension test. Western blot analyses and immunofluorescence staining were used to evaluate protein expression levels of SIRT1, autophagy markers, and the AKT/mTOR., Results: Postpartum depressive-like behavior was triggered following the withdrawal of estradiol benzoate after hormone-stimulated-pregnancy. RSV improved postpartum depressive-like behavior of mice via its upregulation of the SIRT1 and autophagy markers, such as Beclin1, ATG5 and LC3B. Also, the downregulation of the p62 protein expression was observed. More importantly, we also detected the inhibition of phosphorylated AKT and mTOR in the hippocampus of postpartum depressive-like mice., Conclusion: RSV could alleviate postpartum depression-like behavior in mice by stimulating the SIRT1, induce autophagy and inhibit the AKT/ mTOR signaling pathway., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Postpartum depression (PPD) affects 1 in 7 women and has negative mental health consequences for both mother and child. However, the precise biological mechanisms behind the disorder are unknown. Therefore, we performed the largest transcriptome-wide association study (TWAS) for PPD (482 cases, 859 controls) to date using RNA-sequencing in whole blood and deconvoluted cell types. No transcriptional changes were observed in whole blood. B-cells showed a majority of transcriptome-wide significant results (891 transcripts representing 789 genes) with pathway analyses implicating altered B-cell activation and insulin resistance. Integration of other data types revealed cell type-specific DNA methylation loci and disease-associated eQTLs (deQTLs), but not hormones/neuropeptides (estradiol, progesterone, oxytocin, BDNF), serve as regulators for part of the transcriptional differences between cases and controls. Further, deQTLs were enriched for several brain region-specific eQTLs, but no overlap with MDD risk loci was observed. Altogether, our results constitute a convergence of evidence for pathways most affected in PPD with data across different biological mechanisms., (© 2022. The Author(s).)

Postpartum depression (PPD) is the most common type of puerperal mental syndrome and affects maternal physical and mental health and even the growth and development of infants. Paeoniflorin exerts a potential antidepressive effect; however, the functional roles and potential mechanisms of paeoniflorin in PPD are still largely unknown. PPD rat models were prepared by withdrawing hormone‑simulated pregnancy (HSP), and subjects were treated with paeoniflorin and fluoxetine or plasmids. The sucrose preference test (SPT), forced swimming test (FST) and tail suspension test (TST) were used to monitor depression‑like behavior in rats. A radioimmunoassay was utilized for estradiol (E2) and progesterone (P) measurements. ELISA was performed to detect serum corticosterone (Cor), hippocampal allopregnanolone (Allo), IL‑1β and TNF‑α levels. Expression of the E2 receptors ERα and ERβ was detected by qPCR. Western blotting was used to detect TSPO, BDNF and mTOR phosphorylation. Paeoniflorin drastically increased the sucrose preference of rats while decreasing the immobility time in the FST and TST in PPD models. Moreover, paeoniflorin intervention upregulated serum E2, hippocampal Allo, ERα, and ERβ levels but degraded P, serum Cor, IL‑1β, TNF‑α and ERα/ERβ levels. Mechanistically, paeoniflorin promoted TSPO and BDNF‑mTOR pathway activation in PPD rats. Furthermore, suppression of TSPO or the BDNF‑mTOR pathway partially reversed the effects of paeoniflorin on depression‑like behaviors, hormone levels, and inflammatory cytokine release. Paeoniflorin may improve symptoms of PPD by regulating the TSPO and BDNF‑mTOR pathways, indicating that paeoniflorin may be an effective anti‑PPD and antidepressant drug, providing evidence for the future treatment of PPD.

Background: The substantial female hormone fluctuations associated with pregnancy and postpartum have been linked to a greater risk of developing depressive symptoms, particularly in high-risk women (HRW), i.e. those with histories of mood sensitivity to female hormone fluctuations. We have shown that glutamate (Glu) levels in the medial prefrontal cortex (MPFC) decrease during perimenopause, a period of increased risk of developing a major depressive episode. Our team has also demonstrated that percentage gray matter (%GM), another neural correlate of maternal brain health, decreases in the MPFC during pregnancy., Objective: To investigate MPFC Glu levels and %GM from late pregnancy up to 7 weeks postpartum in HRW and healthy pregnant women (HPW)., Methods: Single-voxel spectra were acquired from the MPFC of 41 HPW and 22 HRW using 3- Tesla in vivo proton magnetic resonance spectroscopy at five different time points., Results: We observed a statistically significant interaction between time and group for the metabolite Glu, with Glu levels being lower for HRW during pregnancy and early postpartum (p<0.05). MPFC %GM was initially lower during pregnancy and then significantly increased over time in both groups (p<0.01)., Conclusion: This investigation suggests that the vulnerability towards PPD is associated with unique fluctuations of MPFC Glu levels during pregnancy and early postpartum period. Our results also suggest that the decline in MPFC %GM associated with pregnancy seems to progressively recover over time. Further investigations are needed to determine the specific role that female hormones play on the physiological changes in %GM during pregnancy and postpartum., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Recent evidence has confirmed the association of glucocorticoid receptor (GR) gene variants with the "stress" endocrine axis in postpartum depression (PPD). Sirtuin 1(SIRT1) is an NAD + -dependent histone deacetylase and transcriptional enhancer of GR. However, to date, the function of the SIRT1 gene in the regulation of GR expression in PPD remains to be fully determined. A hormone-stimulated pregnancy (HSP) and subsequent "postpartum" withdrawal of estrogen was employed to mimic the fluctuations in estradiol associated with pregnancy and postpartum. We confirmed that estradiol benzoate withdrawal (EW)-rats displayed depression- and anxiety-like behaviors. These behavioral dysfunctions are associated with attenuated expression of SIRT1 and GR in the hippocampus. To assess the role of SIRT1, as well as its regulatory target directly, a selective SIRT1 activator (SRT2104) was infused into the hippocampus of EW-rats. We found that pharmacological activation of hippocampal SIRT1 blocks the development of depression-related, but not anxiety-related, phenotypes of PPD. In addition, the activation of SIRT1 leads to an increase in hippocampal GR expression in EW-rats. We further confirmed that SIRT1 physically interacts with GR in a glucocorticoid-dependent manner. Taken together, our results suggest that neuropathology in PPD is caused, at least in part, by the inhibition of the SIRT1-GR signaling pathway. Elevating SIRT1 levels, either pharmacologically or through other means, could represent a therapeutic strategy for PPD., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Gestational stress can increase postpartum depression in women. To treat maternal depression, fluoxetine (FLX) is most commonly prescribed. While FLX may be effective for the mother, at high doses it may have adverse effects on the fetus. As environmental enrichment (EE) can reduce maternal stress effects, we hypothesized that a subthreshold dose of FLX increases the impact of EE to reduce anxiety and depression-like behavior in postpartum dams exposed to gestational stress. We evaluated this hypothesis in mice and to assess underlying mechanisms we additionally measured hypothalamic-pituitary-adrenal (HPA) axis function and brain levels of the hormone oxytocin, which are thought to be implicated in postpartum depression. Gestational stress increased anxiety- and depression-like behavior in postpartum dams. This was accompanied by an increase in HPA axis function and a decrease in whole-brain oxytocin levels in dams. A combination of FLX and EE remediated the behavioral, HPA axis and oxytocin changes induced by gestational stress. Central administration of an oxytocin receptor antagonist prevented the remediating effect of FLX + EE, indicating that brain oxytocin contributes to the effect of FLX + EE. These findings suggest that oxytocin is causally involved in FLX + EE mediated remediation of postpartum stress-related behaviors, and HPA axis function in postpartum dams.

Depression onset during and after pregnancy is prevalent and associated with significant implications for maternal, child, and family health. Although environmental risk factors important to the expression of pregnancy-related depression are well known, knowledge of the genetic underpinning is limited. Given the joint contribution of environmental and genetic factors to depression risk liability, DNA methylation presents itself as an ideal biomarker to investigate basic mechanisms and opportunities for translational research to care for pregnancy-related depression health outcomes. This article is an introduction to DNA methylation and its potential to serve as a marker of depression risk during pregnancy and the postpartum. This commentary discusses current clinical uses of DNA methylation-based testing and how it may be applied to perinatal depression clinical care and management., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

For the first time in over three decades, the year 2019 saw the approval of two new classes of antidepressants: Spravato™ esketamine intranasal spray for treatment-resistant depression, and Zulresso® brexanolone infusion against post-partum depression. Although both therapies were granted "breakthrough" designations, topical application of both drugs could offer several advantages over their current routes of administration. However, delivery of their high therapeutic doses (0.5 mg/kg ketamine in 1 h; 90 µg/kg/h brexanolone over 52 h) is unachievable by conventional means. We evaluated physical enhancement techniques such as iontophoresis, microneedle-treatment, and ablative laser for the rapid delivery of ketamine. Additionally, the sustained delivery of brexanolone across microporated skin employing chemical enhancers and novel microemulsions was also accomplished. The target therapeutic flux of ketamine after skin pre-treatment with laser (534.51 ± 146.93 µg/cm 2 ), and the application of anodal iontophoresis (681.93 ± 74.35 µg/cm 2 ) on ablated skin, was observed within one hour. Microporation of skin using laser was more effective than microneedles, for the delivery of ketamine as well as brexanolone. The developed microemulsions resulted in significantly higher transdermal delivery across laser-treated skin. Although brexanolone demonstrated higher solubility in the w/o microemulsion (21.31 ± 0.14 mg/mL) than the o/w microemulsion (10.69 ± 0.09 mg/mL), percutaneous absorption from the o/w microemulsion (6.04 ± 0.16%) was significantly higher than the w/o microemulsion (1.92 ± 0.02%)., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Postpartum depression is a mood disorder with a distinct neurobiological and behavioural profile occurring during and after the postpartum period. Dopamine pathways in the limbic regions of the brain such as the nucleus accumbens (NAc) have been shown to be involved in the etiology of depressive disorders. Selective activation of the dopamine D1-D2 receptor heteromer has been demonsrated to cause depressive- and anxiogenic-like behaviours in rats. The maternal separation model involving three hour daily maternal separation (MS) from pups on PPD 2-15 on anxiety-, depression- and anhedonia-like behaviors in the dams was investigated, together with plasma corticosterone, oxytocin and D1-D2 heteromer expression in the NAc core and shell in non-MS and MS dams. Depression, anxiety and anhedonia-like behaviours were measured using the forced swim test, elevated plus maze and sucrose preference test, respectively. In comparison to non-MS controls, MS dams displayed slightly higher depressive and anxiety-like behaviours with no difference in anhedonia-like behaviours. The MS dams displayed significantly increased care of pups after their retrieval with higher bouts of nursing, lower latency to nurse, lower bouts of out nest behaviour and decreased self-care. There was no significant alteration in D1-D2 heteromer expression in NAc core and shell between mothers of either group (MS, non-MS) or between postpartum rats and nonpregnant female rats, remaining higher than in male rats. This data provides evidence for the maternal separation model in producing a postpartum depression-like profile, but with maternal resilience able to modify behaviours to counteract any potential deleterious consequences to the pups.

Introduction : Postpartum depressive disorder (PPD) is a burdensome medical condition. To date, only one treatment (Brexanolone) has undergone registrational trials and is approved in the United States with an indication for the treatment of PPD. However, other treatments are prescribed and have been tested for this condition. Herein, the authors review the available scientific evidence pertaining to the somatic treatments of PPD. Areas covered : The authors evaluate the published open-label and randomized controlled trials (RCTs), examine the biological mechanisms of PPD treatments, and evaluate how the available data translates into information that may be useful for clinical practice. Expert opinion : Antidepressants have long been the mainstay of PPD treatment, despite the limited evidence from randomized clinical trials that supports this practice. Brexanolone improves treatment options for women with PPD. However, the relatively burdensome administration and monitoring protocol, along with the high cost of the medication, limit the possibility for an extensive use of this medication. Large, randomized, controlled trials of hormonal treatments in patients with PPD are warranted. Also, treatment with mood stabilizers and/or antipsychotics in women with major depressive disorder, who meet the DSM-5 mixed features specifiers in the post-partum period, should be tested in controlled clinical trials.

Stress and ovarian hormone fluctuation are risk factors for postpartum depression (PPD). Previous studies suggested antidepressant-like effects of n-3 polyunsaturated fatty acids (PUFA), but their effect on dam animal with additional stress were not clear. The purpose of the present study was to investigate the hypothesis that n-3 PUFA improved PPD through the serotonergic and glutamatergic pathways by modulating miRNA. Rats were fed n-3 PUFA or control diet from gestation, with pup separation (PS) on postpartum days 2-14 and non-PS controls. N-3 PUFA reversed PS-induced depressive behaviors, including increased immobility, latencies to contact first pup and retrieve all pups, and decreased sucrose preference. N-3 PUFA also modulated the hypothalamic-pituitary-adrenal (HPA) axis by decreasing circulating levels of adrenocorticotropic hormone and corticosterone and expression of hypothalamic corticotrophin releasing factor and hippocampal miRNA-218 but increasing the hippocampal expression of glucocorticoid receptor. N-3 PUFA inhibited neuroinflammation by decreasing circulating levels of prostaglandin E 2 and hippocampal expression of tumor necrosis factor-α, interleukin-6, and miRNA-155. In addition, n-3 PUFA up-regulated the serotonergic pathway by increasing circulating levels of serotonin and hippocampal expression of serotonin-1A receptor, cAMP response element binding protein (CREB), pCREB, brain-derived neurotrophic factor, and miRNA-182 but did not affect the glutamatergic pathway according to the hippocampal expression of N-methyl-D-aspartate receptor-2B. The present study suggested that n-3 PUFA improved PPD through the serotonergic pathway by modifying the HPA axis, neuroinflammation, and related miRNAs., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Perinatal depression (PND) affects approximately 15% of women, and de novo postpartum depression affects approximately 40% of PND cases. Selective serotonin reuptake inhibitors (SSRIs) are a common class of antidepressants prescribed to treat PND. However, the safety and efficacy of SSRIs have been questioned in both clinical and preclinical research. Here, using a preclinical rodent model of de novo postpartum depression, we aim to better understand neuroinflammatory cytokines and tryptophan mechanisms that may be related to SSRI efficacy. Rat dams were treated with high corticosterone (CORT; 40 mg/kg, s.c.) for 22 days in the postpartum period to simulate a depressive-like endophenotype. Concurrently, a subset of dams was treated with the SSRI, fluoxetine (FLX; 10 mg/kg, s.c.), in the postpartum period. We showed, consistent with previous studies, that although maternal FLX treatment prevented CORT-induced disturbances in maternal care behavior during the early postpartum, it failed to prevent the expression of CORT-induced passive coping behavior in the late postpartum. Furthermore, FLX treatment, regardless of CORT treatment, increased maternal hippocampal IL-1β, plasma CXCL1, and decreased maternal plasma tryptophan, 4'-pyridoxic acid, and pyridoxal concentrations. Maternal CORT treatment reduced maternal hippocampal IFN-γ, and both hippocampal and plasma TNF-α. Our work suggests that the limited efficacy of FLX in the late postpartum may be associated with elevated levels of the proinflammatory cytokine IL-1β in the maternal hippocampus, elevated plasma CXCL1, decreased plasma tryptophan concentration, and changes in vitamin B6 dependent tryptophan-kynurenine pathway. These findings suggest novel pathways for improving SSRI efficacy in alleviating perinatal depression., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Postpartum depression (PPD) is a kind of mental disorder characterized by persistent low emotions in puerperium. The most significant physiological change in postpartum is lactation which is regulated by oxytocin receptor (OXTR). However, whether OXTR is related to pathological process of PPD and the potential mechanism still remain unclear. In the present study, we prepared hormone-simulated pregnancy (HSP)-induced PPD mouse model and found that the protein level of OXTR in hippocampus of PPD model mice was down-regulated and Nod-like receptor protein 3 (NLRP3) inflammasome was activated. We identified five long non-coding RNAs (lncRNAs) related to PPD by transcriptome sequencing, including three up-regulated and two down-regulated. The five lncRNAs were associated with the signaling pathway of OXTR according to the bioinformatics analysis. Furthermore, we focused on one of the five lncRNAs, Gm14205, and found that it targeted OXTR which inhibited astrocytic NLRP3 inflammasome activation in hippocampal primary astrocytes. These findings illustrate that OXTR has protective effects in PPD by inhibiting NLRP3 inflammasome activation and provides a new strategy for targeting lncRNA Gm14205 in the pathogenesis of PPD., (© 2020 The Author(s).)

The two hypothalamic neuropeptides oxytocin and melanin concentrating hormone (MCH) share several physiological actions such as the control of maternal care, sexual behavior, and emotions. In this study, we uncover the role for the oxytocin-MCH signaling pathway in mood regulation. We identify discrete effects of oxytocin-MCH signaling on depressive behavior and demonstrate that parenting and mating experiences shape these effects. We show that the selective deletion of OXT receptors from MCH neurons increases and decreases depressive behavior in sexually naïve and late postpartum female mice respectively, with no effect on sexually naïve male mice. We demonstrate that both parenting experience and mood-regulating effects of oxytocin-MCH are associated with synaptic plasticity in the reward and fear circuits revealed by the alterations of Arc expressions, which are associated with the depressive behavior. Finally, we uncover the sex-dependent effects of mating on depressive behavior; while the sexual activity reduces the basal levels of depressive behavior in male mice, it reduces in female mice evoked-depression only. We demonstrate that the oxytocin-MCH pathway mediates the effects of sexual activity on depressive behavior. Our data suggest that the oxytocin-MCH pathway can serve as a potential therapeutic target for the treatment of major depression and postpartum mood disorders.

Translocator protein 18 kDa (TSPO) is mainly distributed in the outer mitochondrial membrane of steroid-synthesizing cells in the central and peripheral nervous systems. It mediates cholesterol transportation across the phospholipid membrane, which is a prerequisite for neurosteroid synthesis. Though the ligand of TSPO has clinical value in the diagnosis and treatment of neuropsychiatric disorders, the pharmacological study of TSPO for anti-postpartum depression has not been reported. In this study, the classical method of reproductive hormone withdrawal was used to construct a rat model of postpartum depression (PPD). The effect of YL-IPA08, a new ligand compound of TSPO, on PPD was evaluated using multiple behavioral tests at progressive time points. Additionally, real-time quantitative PCR, Western-blotting and an enzyme linked immunosorbent assay were conducted to elucidate the potential molecular mechanism of such effect. We report that the levels of TSPO and neurosteroids in the hippocampus and prefrontal cortex were significantly decreased in PPD rats compared to healthy controls. After 3 weeks of drug treatment, the levels of TSPO and neurosteroids in the hippocampus of PPD rats were increased, and anxiety and depressive like behaviors were alleviated. Meanwhile, compared with sertraline treatment, a positive control in this study, YL-IPA08 treatment had a shorter onset time. Our results suggest that the anxiolytic and anti-depressive activity of YL-IPA08 has significant value in the treatment of PPD and that TSPO may be a potential new target for the treatment of PPD.

Objectives: A growing body of data indicates that the kynurenine pathway may play a role in the pathogenesis of postpartum depressive symptoms (PDS). Kynurenic aminotransferase (KAT) is an important kynurenine pathway enzyme, catalyzing kynurenine (KYN) into kynurenic acid (KYNA). This study investigated as to whether genetic variations in KAT are associated with PDS., Methods: A cohort of 360 Chinese women scheduled to undergo cesarean delivery was enrolled into this study. PDS was determined by an Edinburgh Postnatal Depression Scale (EPDS) score ≥ 13. A total of eight KAT single nucleotide polymorphisms (SNPs) were genotyped and their association with PDS investigated. Serum concentrations of KYN, KYNA, and quinolinic acid (QUIN) in women with or without PDS were also measured. This allowed the determination of the KYNA/KYN ratio, which is reflective of KAT activity., Results: Postpartum depressive symptoms incidence was 7.2%. Advanced maternal age, lower education, antenatal depression, and postpartum blues were risk factors for PDS (p < .05). Women with PDS, versus non-PDS, had heightened KYN levels one day prior to surgery (ante-d1) (p < .05), as well as having significantly lower KYNA and higher QUIN levels at postnatal day three (post-d3) (p < .05). Women with, versus without, PDS also had a significantly higher QUIN/KYNA ratio at post-d3 (p < .05). KAT activity was significantly lower in women with, versus without, PDS at ante-d3 (p < .05). No significant association was evident between the KAT SNPs and PDS., Conclusion: Our data support a role for alterations in the kynurenine pathway in the pathogenesis of PDS, although no significant association was found for the eight tested KAT SNPs with PDS., (© 2020 The Authors. Brain and Behavior published by Wiley Periodicals, Inc.)

Introduction: Prevalence of postpartum depression (PPD) ranges from 10 to 15 % of parturients. The impact of the PPD is major on the maternal bond and the health of both mother and child. Its physiopathological mechanisms appear to differ from other types of depression. Today, pharmacotherapy is based on nonspecific treatment, and recent therapeutic advances in this field require a comprehensive approach of the implication of the GABAergic system in the development of PPD. Neurosteroid levels during pregnancy and after parturition and the GABA-A-r modulation are thought to be involved in PPD., Objective: To evaluate if the GABAergic approach is relevant in postpartum depression management., Methods: We conducted a systematic review of literature based on the MEDLINE database with the following Medical Subject Headings (MeSH): "postpartum depression", "GABA", "ganaxolone", "brexanolone", "allopregnanolone", prior to September 2019. We selected articles in English: preclinical and clinical studies, literature review, observational and therapeutic studies., Results: Preclinical models (mouse and rat) show changes in GABAergic inhibition in the peripartum period and correlation between allopregnanolone and GABA-A-r plasticity. This plasticity in the peripartum period maintains levels of inhibition adapted despite increased neurosteroid levels. KO models for the GABA-A-r δ subunit develop depression and anxiety symptoms in the postpartum period, and a change in the expression of the gene coding for the GABA-R alpha-4 subunit was found. Artificial inhibition of progesterone metabolism during post-partum increased depression symptoms. GABAergic fluctuation seems to be interrelated with other systems such as those of oxytocins. A synthetic neurosteroid (SGE-516) was tested on mouse models of PPD, KO for δ-GABA-A-r or KCC2, and showed decreased depressive symptoms and better mothering. Clinical studies confirm neurosteroid fluctuation and changes in the GABAergic system during the peripartum period. Allopregnanolone is the neurosteroid the most studied in PPD, and it is elevated in the brain during the pregnancy. Studies disagree on the presence of significant differences in allopregnanolone plasma levels during pregnancy or postpartum between women with PPD or not. Women with a history of PPD have greater susceptibility to neurosteroid withdrawal. Imagery and genetical data also show a link between allopregnanolone and PPD. The GABA-A-r may not recover in time following a reduced number during pregnancy, and this mismatch between neurosteroid levels and their receptor may trigger PPD. Several randomized controlled trials investigated brexanolone administrated IV, a synthetic formulation of allopregnanolone, and demonstrated a rapid and well tolerated reduction in depressive symptoms. In March 2019 brexanolone obtained FDA approval in PPD indication under the name Zulresso. However, there are differences in the time of beginning of PPD, which could constitute different subgroups of this disease, and which physiopathology could respond to different mechanisms. Prenatal depression does not respond to a GABAergic approach, but women without any risk factor or previous mood disorder developing PPD in the weeks following childbirth could be particularly responsive to this kind of treatment., Conclusion: Disability to modulate GABA-A-r expression during pregnancy and restore its previous state after parturition appears to trigger PPD. The GABAergic system is a promising pharmacotherapy target. From preclinical to clinical studies for about twenty years the GABAergic system has been incriminated and targeted in this challenging mental disease., (Copyright © 2019 L'Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.)

Although postpartum depression (PPD) is the leading cause of disability worldwide, its molecular mechanisms are poorly understood. Recent evidence has suggested that impaired glucocorticoid receptor (GR), the signaling of key molecules of the HPA axis, plays a key role in the behavioral and neuroendorcrine alterations of major depression. However, the role of GR in postpartum period, which following with the abrupt withdrawal of placental corticotropin releasing hormone (CRH) and resulting in a re-equilibration of the maternal HPA axis in the days of post-delivery, is still not entirely clear. Previously, a hormone-simulated pregnancy (HSP), and the subsequent 'postpartum' withdrawal in estrogen has been employed to mimic the fluctuations in estradiol associated with pregnancy and postpartum. Using the HSP model, we investigated here the effect of 'postpartum' withdrawal in estrogen as well as depression- and anxiety-like behavior by intra-hippocampal infusion with GR inhibitor-RU486. Following the successful acquisition of PPD model by withdrawal in estrogen, reduced GR expression was observed in hippocampus. Further, HSP-rats suffered intra-hippocampal RU486 infusion presented depression- and anxiety-like behavior as postpartum depression. Together, these results suggest an important, though complex, role for GR in the behavioral regulation of postpartum depression., Competing Interests: Declaration of competing interest The authors have no conflict of interest to declare., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Depression during pregnancy and the post-partum is common, with severe cases resulting in suicidal behavior. Despite the urgent and unmet medical need, the biological underpinnings of peri-partum depression remain unclear. It has been suggested that it is triggered by dynamic changes of the immune system during pregnancy and at delivery. Therefore, we investigated whether a pro-inflammatory status in plasma, together with changes in the kynurenine pathway activity, is associated with the development of severe depression and suicidal behavior in the post-partum. Our cross-sectional study targets a unique, understudied population in which the pronounced severity of symptoms required hospitalization. We analyzed plasma IL-1β, IL-2, IL-6, IL-8, TNF-α, tryptophan, serotonin, kynurenine, nicotinamide, quinolinic- and kynurenic acids in post-partum women diagnosed with peripartum onset depression (PPD) and healthy controls (n = 165). We assessed depression severity using the Edinburgh Postnatal Depression Scale and suicidality using the Columbia-Suicide Severity Rating Scale. We found that increased plasma IL-6 and IL-8 and reductions of serotonin, IL-2 and quinolinic acid were associated with the severity of depressive symptoms and increased the risk for PPD. Moreover, women with lower serotonin levels were at an increased risk for suicidal behavior, even when adjusting for depression severity, psychosocial factors, age BMI, and medication. Our results indicate that severe depression in the post-partum involves dysregulation of the immune response and the kynurenine pathway, with a concomitant reduction in serotonin levels. We propose that inflammatory cytokines and the kynurenine pathway are potential treatment targets in PPD, opening up the possibility of novel therapeutic strategies targeting the peripartum., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Brexanolone injection, the first therapy approved by the US FDA for the treatment of postpartum depression (PPD) in adults, has been shown to produce a significantly greater decrease in the Hamilton Rating Scale for Depression (HAM-D) total score than placebo in randomised controlled trials (RCTs) of women with PPD., Objectives: Given the rapid effect of brexanolone injection (within 60 h) sustained throughout the length of the trials (30 days), we sought to compare its efficacy data against selective serotonin reuptake inhibitors (SSRIs), the class of antidepressants most commonly prescribed for PPD, using HAM-D and Edinburgh Postnatal Depression Scale (EPDS) outcomes from currently available RCTs., Methods: We extracted data from 26 studies identified in a systematic literature review of pharmacological and pharmacological/nonpharmacological combination therapies in PPD. Six studies were suitable to form evidence networks through which to perform indirect treatment comparisons (ITCs) of HAM-D and EPDS outcomes between brexanolone and SSRIs. Having assessed the comparability and suitability of the available evidence for analysis, we discovered significant heterogeneity in the study designs, most notably in the placebo arms of the trials. We therefore conducted matching-adjusted indirect comparisons (MAICs) between brexanolone and the placebo arms of comparator studies, subsequently using the MAIC results of brexanolone versus placebo, and results for SSRIs versus placebo, to form ITCs of brexanolone versus SSRIs at three separate time points-day 3, week 4 and last observation. ITCs were calculated as the differences in change from baseline (CFB) in HAM-D and, separately, CFB in EPDS, between treatments, and reported with 95% confidence intervals (CIs)., Results: For all time points, MAICs showed larger differences in CFB for brexanolone compared with SSRIs. Differences (95% CIs) between brexanolone and SSRIs were 12.79 (8.04-17.53) [day 3], 5.87 (- 1.62 to 13.37) [week 4] and 0.97 (- 6.35 to 8.30) [last observation] for the HAM-D. For the EPDS, the differences in CFB were 7.98 (5.32-10.64) [day 3], 6.35 (3.13-9.57) [week 4] and 4.05 (0.79-7.31) [last observation]. Other analytical approaches are also presented to demonstrate the similarity of results, using a network meta-analysis approach, and the importance of using the MAIC method to control for the important heterogeneity between placebo arms., Conclusions: Acknowledging the limitations of ITCs and this evidence base, when compared with SSRIs, these analyses suggest that brexanolone demonstrated larger differences in CFB for both patient- and clinician-reported PPD outcomes and at all investigated time points after adjusting for differences between placebos in the included studies.

Objectives: This pilot study aimed to 1) follow the longitudinal changes in the salivary oxytocin level of pregnant women from late pregnancy to early postpartum, 2) examine the factors related to these changes, and 3) clarify the association of these changes with mother-infant bonding., Methods: This study used a longitudinal observational design and questionnaires to obtain objective and subjective data. For oxytocin evaluation, saliva samples were collected and their oxytocin levels were measured at 4-time points [i.e., 1) 36-37 gestation weeks, 2) 38-39 gestation weeks, 3) 1-2 days postpartum, 4) 4-5 days postpartum]. The oxytocin level was assayed in duplicates by enzyme-linked immunosorbent assay. Baseline data were evaluated using the Parental Bonding Instrument (25 items), State Trait Anxiety Inventory (20 items), and Center for Epidemiologic Studies Depression Scale. Postpartum data were evaluated using the Mother to Infant Bonding Scale Japanese Version (10 items), Maternity Blues Scale (13 items), and 'Fatigue after Childbirth' using the Visual Analogue Scale (VAS: 0-100 mm)., Results: The participants were 13 primiparas with a mean age of 33 years. They had no depression or anxiety at the baseline. Their mean salivary oxytocin levels significantly increased from late pregnancy (36-39 gestation weeks) up to 1 day postpartum and then decreased until 5 days postpartum. There was a negligible correlation between the bonding disorder and the salivary oxytocin level on the 5th day after childbirth. A moderate correlation was observed between the maternity blues score and the salivary oxytocin level. There was a significant negative correlation between the postpartum fatigue and the salivary oxytocin level 1 day and 5 days after childbirth., Conclusion: The mean salivary oxytocin levels significantly increased from the baseline up to 1 day postpartum and then decreased until 5 days postpartum. The salivary oxytocin level was moderately associated with maternity blues and significantly with postpartum fatigue., Competing Interests: The authors have declared that no competing interests exist.

Altered reproductive hormone levels have been associated with the pathophysiology of depressive disorders and this risk may be imparted by their modulatory effect upon hippocampal structure and function. Currently it is unclear whether altered levels of reproductive hormones are causally associated with hippocampal volume reductions and the risk of depressive disorders. Here, we utilize genome-wide association study (GWAS) summary statistics from a GWAS focusing on reproductive hormones, consisting of 2913 individuals. Using this data, we generated polygenic risk scores (PRS) for estradiol, progesterone, prolactin and testosterone in the European RADIANT cohort consisting of 176 postpartum depression (PPD) cases (100% female, mean age: 41.6 years old), 2772 major depressive disorder (MDD) cases (68.6% female, mean age: 46.9 years old) and 1588 control participants (62.5% female, mean age: 42.4 years old), for which there was also a neuroimaging subset of 111 individuals (60.4% female, mean age: 50.0 years old). Only the best-fit PRS for estradiol showed a significant negative association with hippocampal volume, as well as many of its individual subfields; including the molecular layer and granule cell layer of the dentate gyrus, subiculum, CA1, CA2/3 and CA4 regions. Interestingly, several of these subfields are implicated in adult hippocampal neurogenesis. When we tested the same estradiol PRS for association with case-control status for PPD or MDD there was no significant relationship observed. Here, we provide evidence that genetic risk for higher plasma estradiol is negatively associated with hippocampal volume, but this does not translate into an increased risk of MDD or PPD. This work suggests that the relationship between reproductive hormones, the hippocampus, and depression is complex, and that there may not be a clear-cut pathway for etiology or risk moderation., (Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Peripartum depression is a common, serious complication in mothers. To assess the influence of infant care, sleep and growth on the risk of peripartum depression, 1,271 mothers of healthy one-month-old infants completed comprehensive questionnaires including the Edinburgh Postnatal Depression Scale. Relationships between high depression scores and variables related to infants' care, sleep and growth were assessed adjusting for other variables. High depression scores were found in 233 mothers, which were associated with variables related to infants' care (poor satisfaction with infant care support, p < 0.001; mothers' passive response to night-time fussing, p = 0.001), sleep (dim bedroom lighting, p < 0.05; short sleep duration, p < 0.05) and growth (poor weight gain, p < 0.05), as well as maternal variables (primiparas, p < 0.001; poor income satisfaction, p < 0.001; poor sleep satisfaction, p < 0.001; daytime sleepiness, p = 0.001). Considering the observed association between high depression scores and infants' care, sleep and growth, a multidisciplinary approach accounting for infant care would be required to prevent peripartum depression.

Research studies have indicated that alterations in plasma progesterone levels might be associated with the hippocampal synaptic plasticity of postpartum depressive-like behavior. Herein, we assess both progesterone and fluoxetine effects in adult female Sprague-Dawley rats with postpartum depressive-like behavior. Depressive-like behavior of postpartum rats was established using chronic ultra-mild stress (CUMS) method for 1 week from gestation day 15. Postpartum rats that showed depressive-like behavior were treated with either progesterone (subcutaneously, 0.5 mg/kg) from gestation day 17 to gestation day 22 or fluoxetine (by gavage, 10 mg/kg/day) for 4 weeks after birth. Open field and sucrose preference tests were conducted at the start, week 2 and week 4 postpartum. Golgi staining, immunofluorescence and Western blot analyses of rats' hippocampi were conducted on week 4 postpartum. Results showed CUMS increases depressive-like behavior, however, treatment with progesterone and fluoxetine improves this behavior. Both progesterone and fluoxetine treatments increase the numbers of dendritic spines pyramidal neurons in the CA3 region of the hippocampus as well as protein expression levels of microtubule-associated protein 2 (MAP-2) and synaptophysin (SYP). CUMS-induced decrement of MAP-2 and SYP protein expressions can be prevented by treatment with progesterone in advanced pregnant stage and fluoxetine in the postpartum period., (© 2019 International Federation for Cell Biology.)

Individual differences in the response of the stress system to hormonal changes during pregnancy and the postpartum period render some women susceptible to developing depression. The present study sought to investigate peripartum depression and stress hormones in relation to stress-related genotypes. The Edinburgh Postnatal Depression Scale was used to assess peripartum depressive symptoms in a sample of 1629 women, followed from pregnancy week seventeen to six months postpartum. Genotypes of ninety-four haplotype-tag single nucleotide polymorphisms (SNPs) in sixteen genes of the hypothalamus-pituitary-adrenal axis pathway were analyzed and data on psychosocial and demographic factors was collected. In sub-studies, salivary cortisol awakening response in gestational week 35-39, salivary evening cortisol levels in gestational week 36 and postpartum week 6, and blood cortisol and cortisone levels in gestational week 35-39 were analyzed. SNP-set kernel association tests were performed at the gene-level, considering psychosocial and demographic factors, followed by post-hoc analyses of SNPs of significant genes. Statistically significant findings at the 0.05 p-level included SNPs in the hydroxysteroid 11-beta dehydrogenase 1 (HSD11B1) gene in relation to self-rated depression scores in postpartum week six among all participants, and serpin family A member 6 (SERPINA6) gene at the same time-point among women with de novo onset of postpartum depression. SNPs in these genes also associated with stress hormone levels during pregnancy. The present study adds knowledge to the neurobiological basis of peripartum depression by systematically assessing SNPs in stress-regulatory genes and stress-hormone levels in a population-based sample of women., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Perinatal depression (PND) is a heterogeneous disorder with differences in timing of onset of depression, which influences symptomology, severity, and treatment efficacy. Researchers must embrace the heterogeneity to bring fruition to a precision medicine approach for women in reproductive mental health care., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Postpartum depression is one of the most common complications of childbirth. Untreated postpartum depression can have substantial adverse effects on the well-being of the mother and child, negatively impacting child cognitive, behavioral, and emotional development with lasting consequences. There are a number of therapeutic interventions for postpartum depression including pharmacotherapy, psychotherapy, neuromodulation, and hormonal therapy among others, most of which have been adapted from the treatment of major depressive disorder outside of the peripartum period. Current evidence of antidepressant treatment for postpartum depression is limited by the small number of randomized clinical trials, underpowered samples, and the lack of long-term follow-up. The peripartum period is characterized by rapid and significant physiological change in plasma levels of endocrine hormones, peptides, and neuroactive steroids. Evidence supporting the role of neuroactive steroids and γ-aminobutyric acid (GABA) in the pathophysiology of postpartum depression led to the investigation of synthetic neuroactive steroids and their analogs as potential treatment for postpartum depression. Brexanolone, a soluble proprietary intravenous preparation of synthetic allopregnanolone, has been developed. A recent series of open-label and placebo-controlled randomized clinical trials of brexanolone in postpartum depression demonstrated a rapid reduction in depressive symptoms, and has led to the submission for regulatory approval to the US Food and Drug Administration (decision due in March 2019). SAGE-217, an allopregnanolone analog, with oral bioavailability, was recently tested in a randomized, double-blind, placebo-controlled phase III study in severe postpartum depression, with reportedly positive results. Finally, a 3β-methylated synthetic analog of allopregnanolone, ganaxolone, is being tested in both intravenous and oral forms, in randomized, double-blind, placebo-controlled phase II studies in severe postpartum depression.

Background: Peripartum major depression (MD) disables mothers and impairs emotional and neurocognitive development of offspring. We tested the hypothesis that critically-timed wake therapy (WT) relieves peripartum MD by altering melatonin and sleep timing, differentially, in antepartum vs. postpartum depressed patients (DP)., Methods: In a university clinical research center, we initially randomized 50 women - 26 antepartum (17 healthy comparison-HC, 9 DP) and 24 postpartum (8 HC, 16 DP) - to a cross-over trial of one night of early-night wake therapy (EWT: sleep 3:00-7:00 am) vs. late-night wake therapy (LWT: sleep 9:00 pm-01:00 am). Ultimately, we obtained mood, overnight plasma melatonin and polysomnography for: 15 antepartum women receiving EWT, 18 receiving LWT; 15 postpartum women receiving EWT, 14 receiving LWT., Results: EWT improved mood more in antepartum vs. postpartum DP in conjunction with reduced (normalized) melatonin-sleep phase-angle differences (PADs) due to delayed melatonin onsets and advanced sleep onsets, and increased (from baseline) total sleep times (TST). LWT improved mood more in postpartum vs. antepartum DP in conjunction with increased TST., Limitations: Small samples potentially rendered the study underpowered to detect group differences, making confirmation with larger samples essential. Sufficient follow-up data were not available in most women to document the duration of the mood response to wake therapy., Conclusions: EWT benefitted antepartum DP more by realigning melatonin and sleep timing, whereas LWT benefitted postpartum DP more by increasing TST. Thus, consistent with precision medicine aims, maximum mood benefits accrue from timing sleep/wake interventions to specific peripartum circadian pathophysiologies., (Copyright © 2018. Published by Elsevier B.V.)

Postpartum depression (PPD) is associated with abnormalities in resting-state functional connectivity (RSFC) but the underlying neurochemistry is unclear. We hypothesized that peripartum GABAergic neuroactive steroids (NAS) are related to cortical GABA concentrations and RSFC in PPD as compared to healthy comparison women (HCW). To test this, we measured RSFC with fMRI and GABA+/Creatine (Cr) concentrations with proton magnetic resonance spectroscopy ( 1 H MRS) in the pregenual anterior cingulate (pgACC) and occipital cortices (OCC) and quantified peripartum plasma NAS. We examined between-group differences in RSFC and the relationship between cortical GABA+/Cr concentrations with RSFC. We investigated the relationship between NAS, RSFC and cortical GABA+/Cr concentrations. Within the default mode network (DMN) an area of the dorsomedial prefrontal cortex (DMPFC) had greater connectivity with the rest of the DMN in PPD (peak voxel: MNI coordinates (2, 58, 32), p = 0.002) and was correlated to depression scores (peak HAM-D17 voxel: MNI coordinates (0, 60, 34), p = 0.008). pgACC GABA+/Cr correlated positively with DMPFC RSFC in a region spanning the right anterior/posterior insula and right temporal pole (r = +0.661, p = 0.000). OCC GABA+/Cr correlated positively with regions spanning both amygdalae (right amygdala: r = +0.522, p = 0.000; left amygdala: r = +0.651, p = 0.000) as well as superior parietal areas. Plasma allopregnanolone was higher in PPD (p = 0.03) and positively correlated with intra DMPFC connectivity (r = +0.548, p = 0.000) but not GABA+/Cr. These results provide initial evidence that PPD is associated with altered DMN connectivity; cortical GABA+/Cr concentrations are associated with postpartum RSFC and allopregnanolone is associated with postpartum intra-DMPFC connectivity.

During the postpartum period, the brain's inhibitory GABAA receptors may not recover in time following their reduced numbers during pregnancy. This is likely the cause of postpartum depression prevalent in ∼12% of childbearing women. A new therapy for this condition consists of administering a synthetic neurosteroid during the postpartum period to alleviate the mood disorder. To view this Bench to Bedside, open or download the PDF., (Copyright © 2018. Published by Elsevier Inc.)

This review aims to summarize the diverse proposed pathophysiological mechanisms contributing to postpartum depression, highlighting both clinical and basic science research findings. The risk factors for developing postpartum depression are discussed, which may provide insight into potential neurobiological underpinnings. The evidence supporting a role for neuroendocrine changes, neuroinflammation, neurotransmitter alterations, circuit dysfunction, and the involvement of genetics and epigenetics in the pathophysiology of postpartum depression are discussed. This review integrates clinical and preclinical findings and highlights the diversity in the patient population, in which numerous pathophysiological changes may contribute to this disorder. Finally, we attempt to integrate these findings to understand how diverse neurobiological changes may contribute to a common pathological phenotype. This review is meant to serve as a comprehensive resource reviewing the proposed pathophysiological mechanisms underlying postpartum depression., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Our knowledge on the bioavailability and actions of insulin-like growth factor-1 (IGF-1) has markedly expanded in recent years as novel mechanisms were discovered on IGF binding proteins (IGFBPs) and their ability to release IGF-1. The new discoveries allowed a better understanding of the endogenous physiological actions of IGF-1 and also its applicability in therapeutics. The focus of the present review is to summarize novel findings on the neuronal, neuroendocrine and neuroplastic actions of IGF-1 in the adult brain. As most of the new regulatory mechanisms were described in the periphery, their implications on brain IGF system will also be covered. In addition, novel findings on the effects of IGF-1 on lactation and maternal behavior are described. Based on the enormous neuroplastic changes related to the peripartum period, IGF-1 has great but largely unexplored potential in maternal adaptation of the brain, which is highlighted in the present review., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Breastfeeding is associated with positive maternal and infant outcomes. It is recommended that women exclusively breastfeed for the first 6 months postpartum; however, these recommendations are not met in the majority of women. Psychological distress in pregnancy is associated with lower rates of breastfeeding initiation and duration in the postpartum period. The mechanisms linking maternal distress to breastfeeding are not understood. In this study we examined maternal circadian cortisol as a mechanism linking distress in pregnancy to breastfeeding. This study is a secondary data analysis of 197 pregnant women with singleton pregnancies who were part of a larger study of the effects of maternal mood on fetal and infant development. About 34% of women reported exclusively breastfeeding, 18% reported exclusively formula feeding, and 48% reported mixed feeding. Participants reported on perceived stress, perinatal anxiety and depression, and socioeconomic status during pregnancy. They provided salivary cortisol samples at three times a day for 3 days at 24, 30, and 36 weeks' gestation. Participants who reported lower socioeconomic status in pregnancy were less likely to breastfeed, and lower maternal cortisol awakening responses mediated this association. This area of research may identify foci in the prenatal period that could serve as targets for interventions to increase rates of breastfeeding. Lay summary Pregnant women who reported lower socioeconomic status in pregnancy were less likely to breastfeed. This association was mediated by lower cortisol awakening responses, but not evening cortisol levels, over pregnancy.

The transition to motherhood is characterized by some of the most pronounced endocrine changes a woman will experience in her lifetime. Unfortunately, matrescence is also a time in a woman's life when she is most susceptible to mental illness such as perinatal depression. A growing body of research has aimed to determine how key endocrine systems, such as the hypothalamic-pituitary-adrenal (HPA) axis, are involved in the dysregulation of perinatal mental health. However, very little research has consistently linked perinatal changes in the HPA axis with maternal mental illness. Therefore, the aims of this mini review are to: (i) clearly summarize the normative changes in the HPA axis that occur during pregnancy and the postpartum period; (ii) summarize what we know about the HPA axis in perinatal depression, and (iii) propose key areas for future research. Understanding physiological biomarkers that can predict which women are at risk for perinatal mood disorders will lead to better tools for treating, and ultimately preventing, these debilitating disorders, improving the health of mother, child, and family.