Inflammatory pathophysiological mechanisms implicated in postpartum depression

Closer look at the cardiovascular and metabolic predictors of postpartum depression

Postpartum depression (PPD) is a severe mental health disorder affecting 10% to 15% of postpartum women worldwide. Pre-eclampsia is a hypertensive disorder of pregnancy that has been identified as a significant factor for PPD due to its vascular dysfunction, systemic inflammation and neurobiological alterations. The neuroinflammatory mechanisms common to both pre-eclampsia and PPD, that contribute to depressive symptoms include elevated proinflammatory cytokines (interleukin-6, tumor necrosis factor-alpha), activation of the kynurenine pathway, and oxidative stress. To critically evaluate Wu et al's study, which investigates blood pressure variability (BPV) and gestational body mass index (BMI) as independent predictors of PPD. To integrate recent findings on the metabolic and cardiovascular links between depression, pre-eclampsia, and postpartum mental health outcomes. Pre-pregnancy BMI is found to be a stronger predictor of PPD than gestational weight gain. A vascular-neuropsychiatric connection has been indicated in pre-eclamptic women, indicating a significant correlation between BPV and depressive postpartum symptoms. There is increased susceptibility to depression due to neuroinflammation contributed by blood pressure fluctuations and metabolic dysregulation. The incidence of PPD could be reduced by early identification and intervention for BP fluctuations. Early detection and intervention in high-risk pregnancies should be conducted through public health strategies that prioritize awareness, education, and accessibility to mental health care.

Association between dietary inflammatory index and the risk of postpartum depression in China

BACKGROUND

Postpartum depression (PPD) affects numerous women globally, impairing maternal and infant health and contributing to substantial socioeconomic burdens on both families and society. This study aimed to investigate the association between the Dietary Inflammatory Index (DII) and PPD in Chinese women, and explore whether inflammatory cytokines mediate this association.

METHODS

The study recruited 2038 participants and collected data from them. The Chinese version of the Self-Rating Depression Scale was used to assess postpartum depressive symptoms, and the DII scores were evaluated using semi-quantitative food frequency questionnaires (FFQ). To ensure balanced groups, researchers performed propensity score matching. From the matched participants, 126 blood samples were collected to determine serum levels of C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6. Researchers used logistic regression to estimate the odds ratios (OR) and 95 % confidence intervals (CI) between the DII tertiles, inflammatory markers, and PPD. Finally, researchers conducted a mediation analysis using the bootstrap method to examine the relationship between DII, inflammation, and PPD.

RESULTS

Among 2038 participants, 742 (36.4 %) participants were identified as having PPD symptoms. The higher DII scores were associated with PPD, and its significance still exists after a series of factors were adjusted (T2 vs T1: OR = 1.24, 95 % CI: 0.99, 1.55, P > 0.05; T3 vs T1: OR = 1.33, 95 % CI: 1.06, 1.66, P < 0.05). In addition, a higher level of CRP was associated with increased odds of PPD (OR = 1.34, 95 % CI: 1.13, 1.59, P < 0.05). The mediation analysis showed that a direct effect of DII on PPD persisted, and CRP mediated the relationship between DII and PPD.

CONCLUSIONS

A higher DII was associated with an increased risk of PPD in Chinese women. The present finding reinforces the importance of limiting pro-inflammatory food consumed and adopting an anti-inflammatory diet to decrease the risk of PPD.

Postpartum dams exposed to a low-resource environment display neuroinflammation, elevated corticosterone, and anhedonia-like behavior

Women living in an impoverished environment after birth have an increased risk of developing postpartum depression (PP-Dep) and hypertension (PP-HTN). The mechanisms underlying these heightened risks are unknown and understudied. To examine the relation between reduced environmental resources, PP-Dep, and PP-HTN, postpartum rodent dams were exposed to the low-resource limited bedding and nesting (LBN) chronic stress model during weaning. Postpartum dams were divided into control (CTL) and experimental (LBN) groups, in which the experimental group experienced LBN. At 6 wks postpartum, blood pressure, sucrose preference tests (a proxy for anhedonia and depression), corticosterone, and markers of neuroinflammation were measured. We hypothesized that postpartum dams exposed to LBN will have increased corticosterone, neuroinflammation, depression-like behaviors, and HTN. Results show that postpartum dams exposed to an impoverished environment exhibit decreased sucrose preference, increased circulating corticosterone, and elevated neuroinflammation (∼150% increased TNF-α and astrocyte activation in the cerebrum). No changes in blood pressure were observed. However, there was a strong correlation between postpartum blood pressure and corticosterone and blood pressure and TNF-α levels. Importantly, this study provides insights into the pathology and development of PP-HTN and PP-Dep in the postpartum period, which will enable the discovery of novel therapeutic approaches.NEW & NOTEWORTHY Postpartum dams exposed to a low-resource environment experience anhedonia, elevated corticosterone, and neuroinflammation. Increases in corticosterone and neuroinflammation may contribute to the development of postpartum depression (PP-Dep) and postpartum hypertension (PP-HTN). Healthcare providers should consider asking questions about the social economic status and accessibility of resources for women after pregnancy. This study advocates for extended postpartum care beyond traditional care and better implementation of assessments for PP-Dep and PP-HTN.

Exploring potential causal relationships between gut microbiota, inflammatory factors, and postpartum depression: a Mendelian randomization analysis

BACKGROUND

Recent studies have suggested a potential correlation between ecological dysregulation of the gut microbiota (GM) and the onset and development of postpartum depression (PPD). In addition, inflammatory factors (IFs) have been reported to play an important role in the development of PPD. However, the causal connections among GM, IFs, and PPD remain to be understood.

OBJECTIVE

This study sought to determine if genetically predicted GM and IFs exert a causal effect on PPD and to study whether IFs mediate the causal effect of GM on PPD.

METHODS

Two-step and two-sample Mendelian randomization (MR) analyses, primarily employing the inverse variance weighted (IVW) method, were conducted to evaluate the causal relationship between GM, IFs, and PPD, and to assess potential mediating effects. Heterogeneity and horizontal pleiotropy tests were performed to evaluate the robustness of the findings and the strength of the causal associations.

RESULTS

Class Alphaproteobacteria, genus Family XIII AD3011 group exhibited a positive association with PPD risk; whereas, the family Clostridiales vadin BB60 group, family Veillonellaceae, genus Ruminococcaceae UCG011, and the inflammatory factors C-C motif chemokine ligand 5 (CCL5) and C-C motif chemokine ligand 3 (CCL3) demonstrated negative correlations with PPD risk. IFs did not exhibit a mediating role. No heterogeneity or horizontal pleiotropy was observed.

CONCLUSIONS

Our MR study offered genetic evidence that GM and IFs contribute to the pathogenesis of PPD, with no mediating effect of IFs. This enhances our understanding of PPD's pathological mechanisms and offers new perspectives for developing novel preventative and therapeutic strategies.

Conventional and new immunotherapies for immune system dysregulation in postpartum mood disorders: comparisons to immune system dysregulations in bipolar disorder, major depression, and postpartum autoimmune thyroid disease

INTRODUCTION

Postpartum mood disorders are heterogenous disorders and comprise postpartum psychosis and postpartum depression. Evidence is accumulating that systemic monocyte/macrophage activation, low-grade inflammation and (premature senescence related) T cell defects increase the risk for mood disorders outside pregnancy by affecting the function of microglia and T cells in the emotional brain (the cortico-limbic system) leading to inadequate mood regulation upon stress.

AREAS COVERED

The evidence in the literature that similar immune dysregulations are present in postpartum mood disorders.

RESULTS

The physiological postpartum period is characterized by a rapid T cell surge and a mild activation of the monocyte/macrophage system. Postpartum mood disorder patients show a diminished T cell surge (including that of T regulatory cells) and an increase in low grade inflammation, that is, an increased inflammatory state of monocytes/macrophages and higher levels of serum pro-inflammatory cytokines.

EXPERT OPINION

Anti-inflammatory agents (e.g. COX-2 inhibitors) and T cell boosting agents (e.g. low-dose IL-2 therapy) should be further investigated as treatment. The hypothesis should be investigated that postpartum mood disorders are active episodes (triggered by changes in the postpartum immuno-endocrine milieu) in ongoing, dynamically fluctuating aberrant neuro-immune-endocrine trajectories leading to mood disorders in women (inheritably) vulnerable to these disorders.

Peripartum Depression: What's New?

PURPOSE OF THE REVIEW

Peripartum depression (PPD), including both depression during pregnancy and postpartum, is the most frequent health disorder during the perinatal period. It is a significant public health issue in many countries due to its prevalence and its impact on women, as well as on their partners and offspring. Here, we will attempt to untangle the most recent studies and publications, considering what it is essential to know in 2024 about PPD as a specific perinatal issue.

RECENT FINDINGS

PPD appears to be a very heterogeneous disorder in which a complex interplay between different factors contributes to its pathophysiology. Thus, the need to enhance diagnosis and referral through a better understanding of its severity and co-morbidities has emerged as a major public health issue. Indeed, research has consistently shown that PPD negatively impacts parent-infant interactions and infants' cognitive, social, and emotional development. Evidence underlining its global risk has accumulated over the past three decades, but many questions remain, including how these vulnerable offspring developmental trajectories unfold.

The pathophysiology of estrogen in perinatal depression: conceptual update

PURPOSE

Estrogen levels fall sharply after parturition and have long been considered an etiologic contributor to postpartum depression (PPD); however, no differences have been reported in plasma hormone concentrations in people who develop PPD. We examine the question: What is the current view of estrogen and the neurophysiologic processes it impacts in the development and treatment of PPD?

METHODS

A literature review of the role of estrogen on candidate hormonal and epigenetic systems in the peripartum period was performed, including landmark historical studies and recent publications on estrogen-related research. The authors reviewed these papers and participated in reaching consensus on a conceptual framework of estrogen activity within the complexity of pregnancy physiology to examine its potential role for driving novel interventions.

RESULTS

Estrogen fluctuations must be conceptualized in the context of multiple dramatic and interacting changes inherent in pregnancy and after birth, including progesterone, corticosteroids, inflammation, circadian biology and psychosocial challenges. Individuals who develop PPD have increased sensitivity to epigenetic alteration at estrogen-responsive genes, and these changes are highly predictive of PPD. An effective estrogen-based treatment for PPD has yet to be found, but interventions focused on associated inflammation and circadian rhythms are promising.

CONCLUSIONS

Our understanding of the biological basis of PPD, one of the most common morbidities of the perinatal period, is expanding beyond changes in gynecologic hormone concentrations to include their impact on other systems. This growing understanding of the many processes influencing PPD will allow for the development of novel prevention and treatment strategies.

Social Support and Postpartum Depressive Symptoms in Portuguese Women: The Mediating Role of Emotion Regulation Difficulties

Background/Objectives: Postpartum depression (PPD) is a prevalent mental health issue affecting 14% of mothers worldwide, with long-term implications for both maternal and child well-being. Understanding the factors contributing to PPD is essential for developing effective interventions. This study aimed to investigate the relationship between social support and postpartum depression symptoms, with a focus on the mediating role of emotion regulation difficulties. Methods: A sample of 160 postpartum women (M age = 33.57, SD = 4.94) participated in the study. Participants were assessed on their levels of perceived social support, difficulties in emotion regulation, and symptoms of PPD. Results: The results indicated that lower levels of social support were significantly associated with greater difficulties in emotion regulation (effects ranging from -0.10 to 0.07). These difficulties in turn were linked to higher levels of postpartum depression symptoms (effects ranging from -0.29 to 0.78), suggesting a partial mediation effect from emotional awareness (95% CI -0.05, -0.00), non-acceptance of emotions (95% CI -0.04, -0.00), difficulty in goal-directed behavior (95% CI -0.04, -0.00), and limited access to strategies (95% CI -0.12, -0.04). Conclusions: These findings underscore the critical role of both social support and emotion regulation in the development of PPD symptoms. Enhancing emotion regulation skills, particularly for women with limited social support, could be a key target for interventions aimed at reducing the risk and severity of PPD.

Disentangling the Genetic Landscape of Peripartum Depression: A Multi-Polygenic Machine Learning Approach on an Italian Sample

BACKGROUND

The genetic determinants of peripartum depression (PPD) are not fully understood. Using a multi-polygenic score approach, we characterized the relationship between genome-wide information and the history of PPD in patients with mood disorders, with the hypothesis that multiple polygenic risk scores (PRSs) could potentially influence the development of PPD.

METHODS

We calculated 341 PRSs for 178 parous mood disorder inpatients affected by major depressive disorder (MDD) or bipolar disorder (BD) with (n = 62) and without (n = 116) a history of PPD. We used partial least squares regression in a novel machine learning pipeline to rank PRSs based on their contribution to the prediction of PPD, in the whole sample and separately in the two diagnostic groups.

RESULTS

The PLS linear regression in the whole sample defined a model explaining 27.12% of the variance in the presence of PPD history, 56.73% of variance among MDD, and 42.96% of variance in BD. Our findings highlight that multiple genetic factors related to circadian rhythms, inflammation, and psychiatric diagnoses are top contributors to the prediction of PPD. Specifically, in MDD, the top contributing PRS was monocyte count, while in BD, it was chronotype, with PRSs for inflammation and psychiatric diagnoses significantly contributing to both groups.

CONCLUSIONS

These results confirm previous literature about the immune system dysregulation in postpartum mood disorders, and shed light on which genetic factors are involved in the pathophysiology of PPD.

Factors Associated with Postpartum Depression among Women in Eastern Sudan: A Cross-Sectional Study

Background and Objectives: Postpartum depression is one of the most common complications of childbirth. While the epidemiology of postpartum depression has been extensively studied in African countries, there is little published data on the topic in Sudan. In addition, no studies have been conducted in Eastern Sudan. This study aims to evaluate the factors associated with postpartum depression among Sudanese women in Gadarif in Eastern Sudan. Materials and Methods: A cross-sectional study (using the systematic random sampling technique) of women presenting to Gadarif Maternity Hospital for postnatal follow-up within six weeks of childbirth was conducted. A questionnaire was used to collect sociodemographic information, and the Edinburgh Postnatal Depression Scale was used to assess postpartum depression. Results: Three hundred women were enrolled in the study. The median (interquartile) age and parity were 30.0 (25.0-34.0) years and 2 (1-4). Thirty-one (10.3%) of the women had postpartum depression. A univariate analysis showed that a past history of depression was the only factor associated with postpartum depression (OR = 3.04, 95% CI = 1.03-8.97). Other investigated factors (age, parity, educational level, occupation, history of previous miscarriage or intrauterine fetal death, a family history of depression, financial support, medical insurance, whether the pregnancy was planned or not, and if the gender of the newborn was known before delivery) were not associated with postpartum depression. Conclusions: The current study showed that 1 out of 10 women had postpartum depression that was associated with a past history of depression. Factors that have been reported to be associated with postpartum depression in African countries (age, parity, education, and occupation) were not found to be associated in this study. Mental health assessment needs to be employed for women in their antenatal and postpartum periods.

Depression in pregnant Hispanic women: Risk factors, pregnancy outcomes and plasma cytokines

Background

Maternal depression is considered a major contributor to morbidity and mortality in pregnancy. A population at risk are U.S. born or immigrant Hispanic women, and few prenatal depression or immune studies have focused on this population.

Objective

The research questions for the study were 1) What are the occurrences, risk factors and outcomes associated with depression in Hispanic pregnant women in the United States and 2) What are the associations of plasma immune cytokines and prenatal depression in this population.

Study design

Women of self-reported Hispanic ethnicity were born in the continental United States or foreign-born. Screening of potential participants (n = 690) at a first prenatal clinic visit consisted of antibody testing for Toxoplasma gondii antibodies in a larger grant, and only the women with antibody levels below the cutoff for T. gondii positivity (N = 536) were included in the present study. All participants completed a health and demographic questionnaire, the Edinburgh Postpartum Depression (EPDS) scale, the Perceived Stress Scale (PSS), and the Medical Outcomes Study Social Support (MOS) scale. We surveyed electronic health records (EHR) for risk factors and adverse pregnancy outcomes in the sample. We further measured physical and mental health and seven plasma immune cytokines at four study visits during pregnancy in a longitudinal subsample (N = 128).

Results

The frequency of EPDS scores of 10 (depression risk) or above was 18.6 % at the time of enrollment. Socioeconomic factors such as less education, greater unemployment, and U.S. born nativity were associated with greater depression risk, but these relationships became insignificant when we corrected for false discovery rate. Depression scores were not associated with adverse birth and pregnancy outcomes. The inflammatory cytokine TNF-α was significantly higher across pregnancy in women with depression risk (p < 0.03). Other inflammatory cytokines were higher in depressed women, but only at one time point in mid-pregnancy.

Conclusions

Prenatal depression occurs in early pregnancy and then declines in Hispanic women. The frequency of depression and stress were higher in U.S. born compared to immigrant Hispanic women. There was an elevation in plasma levels of TNF-α through the pregnancy in depressed women, and elevations in other cytokines, at midpregnancy. The adverse pregnancy outcomes, including preterm delivery, known to be associated with prenatal depression were not present in this cohort.

Role of Glial Cells in Neuronal Function, Mood Disorders, and Drug Addiction

Mood disorders and substance use disorder (SUD) are of immense medical and social concern. Although significant progress on neuronal involvement in mood and reward circuitries has been achieved, it is only relatively recently that the role of glia in these disorders has attracted attention. Detailed understanding of the glial functions in these devastating diseases could offer novel interventions. Here, following a brief review of circuitries involved in mood regulation and reward perception, the specific contributions of neurotrophic factors, neuroinflammation, and gut microbiota to these diseases are highlighted. In this context, the role of specific glial cells (e.g., microglia, astroglia, oligodendrocytes, and synantocytes) on phenotypic manifestation of mood disorders or SUD are emphasized. In addition, use of this knowledge in the potential development of novel therapeutics is touched upon.

919 granules improve postpartum depression through the regulation of abnormal peripheral blood IL-1β

Postpartum depression (PPD) has a significant impact on the physical and mental health of mothers, potentially leading to symptoms such as low mood, fatigue, and decreased appetite. It may also affect the healthy growth of the infant. The onset of PPD is closely related to abnormalities in inflammation and the immune system. PPD patients exhibit abnormalities in the proportion of peripheral blood immune cells, along with an increase in pro-inflammatory cytokines. Excessive pro-inflammatory cytokines in peripheral blood can disrupt the blood-brain barrier (BBB) by activating astrocytes and reducing transendothelial electrical resistance (TEER), allowing peripheral immune cells or cytokines to enter the brain and trigger inflammation, ultimately leading to the onset of depression. In addition, PPD lacks safe and effective treatment medications. In this study, we collected peripheral blood from both healthy postpartum women and those with PPD, conducted single cell RNA sequencing (scRNA-seq), and used an in-house analytical tool scSTAR to reveal that PPD patients exhibit elevated proportions of peripheral blood cDC2 and Proliferation B cells, which are significantly correlated with IL-1β. Additionally, animal experiments were designed to validate that 919 granules can improve PPD by modulating the levels of peripheral blood IL-1β, providing a potential therapeutic mechanism for PPD treatment.

Activation of σ-1 receptor mitigates estrogen withdrawal-induced anxiety/depressive-like behavior in mice via restoration of GABA/glutamate signaling and neuroplasticity in the hippocampus

Postpartum depression (PPD) is a significant contributor to maternal morbidity and mortality. The Sigma-1 (σ-1) receptor has received increasing attention in recent years because of its ability to link different signaling systems and exert its function in the brain through chaperone actions, especially in neuropsychiatric disorders. YL-0919, a novel σ-1 receptor agonist developed by our institute, has shown antidepressive and anxiolytic effects in a variety of animal models, but effects on PPD have not been revealed. In the present study, excitatory/inhibitory signaling in the hippocampus was reflected by GABA and glutamate and their associated excitatory-inhibitory receptor proteins, the HPA axis hormones in the hippocampus were assessed by ELISA. Finally, immunofluorescence for markers of newborn neuron were undertaken in the dentate gyri, along with dendritic spine staining and dendritic arborization tracing. YL-0919 rapidly improves anxiety and depressive-like behavior in PPD-like mice within one week, along with normalizing the excitation/inhibition signaling as well as the HPA axis activity. YL-0919 rescued the decrease in hippocampal dendritic complexity and spine density induced by estrogen withdrawal. The study results suggest that YL-0919 elicits a therapeutic effect on PPD-like mice; therefore, the σ-1 receptor may be a novel promising target for PPD treatment in the future.

Effect of the sEH inhibitor AUDA on arachidonic acid metabolism and NF-κB signaling of rats with postpartum depression-like behavior

OBJECTIVE

To investigate whether sEH inhibitor AUDA can mitigate postpartum depression (PPD)-like symptoms in the rat model and regulate the AA/NF-κB pathway to suppress the inflammatory response in the prefrontal lobes of PPD rats.

METHODS

Five groups of Sprague Dawley rats were used: normal, sham operated, PPD model, AUDA, and paroxetine hydrochloride. During the 21-day treatment period, animals in all groups underwent assessments (open field test, forced swimming test, and sucrose consumption) for depression-like behavior. At the conclusion of the treatment period, animals in all study groups were euthanized and various proteins in the prefrontal lobes were measured.

RESULTS

Depression-like behavior in rats was attenuated by AUDA. In the prefrontal lobes of PPD rats, levels of 5-LOX, COX-2, sEH, IL-1β, IL- 6, p65, p-p65, P-IκBα, NF-κB p65, and GFAP were increased while levels of epoxyeicosatrienoic acids and 5-HT were decreased. AUDA reversed these changes, thus having a similar effect as the classic antidepressant paroxetine hydrochloride.

CONCLUSION

AUDA may constrain AA/NF-κB in the prefrontal cortex of PPD rats, thus inhibiting the inflammatory response and ultimately attenuating postpartum depression-like behavior.

Biomarkers of Postpartum Depression: A Narrative Review

Postpartum depression (PPD) is a disorder that impairs the formation of the relationship between mother and child, and reduces the quality of life for affected women to a functionally significant degree. Studying markers associated with PPD can help in early detection, prevention, or monitoring treatment. The purpose of this paper is to review biomarkers linked to PPD and to present selected theories on the pathogenesis of the disease based on data from biomarker studies. The complex etiology of the disorder reduces the specificity and sensitivity of markers, but they remain a valuable source of information to help clinicians. The biggest challenge of the future will be to translate high-tech methods for detecting markers associated with postpartum depression into more readily available and less costly ones. Population-based studies are needed to test the utility of potential PPD markers.

The efficacy and safety of some new GABAkines for treatment of depression: A systematic review and meta-analysis from randomized controlled trials

Positive allosteric modulators of γ-aminobutyric acid-A (GABAA) receptors, or GABAkines, play important roles in the treatment of depression, epilepsy, insomnia, and other disorders. Recently, some new GABAkines (zuranolone and brexanolone) have been administrated to patients with major depressive disorder (MDD) or postpartum depression (PPD) in randomized controlled trials (RCTs). This study aims to systematically review and examine the efficacy and safety of zuranolone or brexanolone for treatment of depression. A systematic literature retrieval was conducted through August 20, 2023. RCTs evaluating the efficacy and safety of zuranolone or brexanolone for treatment of depression were included. Eight studies (nine reports) were identified in the study. The percentages of patients with PPD achieving Hamilton Depression Rating Scale (HAM-D) response and remission were significantly higher after brexanolone or zuranolone administration compared with placebo at different points. The percentages of patients with MDD achieving HAM-D response and remission were significantly increased during the zuranolone treatment period compared with placebo. In addition, zuranolone caused more adverse events in patients with MDD compared with placebo. Our findings support the effects of brexanolone on improving the core symptoms of depression in patients with PPD, and the potential of zuranolone in treating patients with MDD or PPD.