DNA methylation biomarkers prospectively predict both antenatal and postpartum depression

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.

Identifying Depression Through Machine Learning Analysis of Omics Data: Scoping Review

BACKGROUND

Depression is one of the most common mental disorders that affects >300 million people worldwide. There is a shortage of providers trained in the provision of mental health care, and the nursing workforce is essential in filling this gap. The diagnosis of depression relies heavily on self-reported symptoms and clinical interviews, which are subject to implicit biases. The omics methods, including genomics, transcriptomics, epigenomics, and microbiomics, are novel methods for identifying the biological underpinnings of depression. Machine learning is used to analyze genomic data that includes large, heterogeneous, and multidimensional data sets.

OBJECTIVE

This scoping review aims to review the existing literature on machine learning methods for omics data analysis to identify individuals with depression, with the goal of providing insight into alternative objective and driven insights into the diagnostic process for depression.

METHODS

This scoping review was reported following the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews) guidelines. Searches were conducted in 3 databases to identify relevant publications. A total of 3 independent researchers performed screening, and discrepancies were resolved by consensus. Critical appraisal was performed using the Joanna Briggs Institute Critical Appraisal Checklist for Analytical Cross-Sectional Studies.

RESULTS

The screening process identified 15 relevant papers. The omics methods included genomics, transcriptomics, epigenomics, multiomics, and microbiomics, and machine learning methods included random forest, support vector machine, k-nearest neighbor, and artificial neural network.

CONCLUSIONS

The findings of this scoping review indicate that the omics methods had similar performance in identifying omics variants associated with depression. All machine learning methods performed well based on their performance metrics. When variants in omics data are associated with an increased risk of depression, the important next step is for clinicians, especially nurses, to assess individuals for symptoms of depression and provide a diagnosis and any necessary treatment.

Metabolites of progesterone in pregnancy: Associations with perinatal anxiety

BACKGROUND

Anxiety disorders are the most common psychiatric disorder during the perinatal period and one of the major risk factors for postpartum depression, yet we know little about biological factors in the etiology of perinatal anxiety. A growing literature points to neuroactive steroid (NAS) dysregulation in perinatal mental illness, but directionality has not been clearly demonstrated, results are not consistent, and no studies have investigated NAS in a population with pure anxiety without comorbid depression. We aimed to add to the limited literature by examining the association between anxiety without comorbid depression and metabolic pathways of NAS longitudinally across the peripartum.

METHODS

We measured anxiety symptoms by psychological scales and NAS levels using Gas Chromatography-Mass Spectrometry (GC-MS) at the second and third trimester (T2 and T3) and week 6 postpartum (W6) in n = 36 women with anxiety and n = 38 healthy controls. The anxiety group was determined by a data-driven approach, and cross-sectional and longitudinal statistical methods were used to examine the relationship between the study population and NAS.

RESULTS

We found that anxiety had a significant moderating effect on the relationship between progesterone and allopregnanolone, with no such effect for the relationships between progesterone and the intermediate (5α-DHP) or isomeric (isoallopregnanolone) compounds in this pathway, and no effects on the corresponding pathway converting progesterone to pregnanolone and epipregnanolone. We also found a less precipitous decline in the ratio of allopregnanolone to progesterone between T3 and W6 in the anxiety group compared to the non-anxiety group. A genotype analysis of a single-nucleotide polymorphism in the AKR1C2 gene demonstrated that the relationship of allopregnanolone to the intermediate metabolite, 5α-DHP, differed by genotype.

CONCLUSION

Our exploratory findings indicate that, for pregnant people with anxiety, metabolism is shunted more aggressively toward the endpoint of the progesterone to allopregnanolone metabolic pathway than it is for those without anxiety.

The role of gut microbiota in the pathogenesis and treatment of postpartum depression

Postpartum depression (PPD) is a common complication of pregnancy in women, and its pathogenesis mainly involves disturbances of the neuroendocrine regulation, immune system, neurotransmitters, hormone secretion, and the gut microbiome. Gut microbes play essential physiological and pathological roles in the gut-brain axis' pathways which are involved in various central nervous system (CNS) and psychiatric disorders, including PPD. Numerous studies have identified the fundamental role of the gut-brain axis in the pathogenesis and treatment of PPD patients and also correlates with other pathogenic mechanisms of PPD. Disturbances in gut microbes are associated with the disruption of multiple signaling pathways and systems that ultimately lead to PPD development. This review aimed to elucidate the potential connections between gut microbes and the established PPD network, and this might serve as a guide for the development of new efficient diagnostic, therapeutic, and prognostic strategies in the management of PPD.

Longitudinal Course of Sex Steroids From Pregnancy to Postpartum

CONTEXT

Sex steroids (SS) typically rise during pregnancy and decline after birth, but no consistent reference values exist for these hormonal courses. We aimed to establish an overview of SS secretion patterns during the peripartum and to better understand how SS contribute to maternal and fetal pathologies.

EVIDENCE ACQUISITION

A systematic literature search was conducted in accordance with the PRISMA guidelines using PubMed, Cochrane Library, and PsycINFO. Additionally, we conducted a supplementary manual search of references. Observational studies published in English and assessing estradiol, progesterone, and testosterone over the course of the peripartum in physically healthy female subjects were included, without restrictions on year of publication. Extracted data were analyzed descriptively and visually.

EVIDENCE SYNTHESIS

SS increase progressively during pregnancy, with an extremely wide range of reported concentrations, especially in the third trimester. In fact, reported concentrations varied up to 5000-fold at comparable measurement time points.

CONCLUSIONS

A comprehensive understanding of the influence of SS levels on associated maternal and fetal pathologies is currently hindered by 2 main factors. First, reported SS levels vary widely during the peripartum period. Second, the current state of knowledge on how SS are associated with pathologies in mothers and babies is largely based on correlational studies, and causality thus remains unclear. Consequently, we recommend the development of a systematic reference framework that follows the suggestions presented in this review. This would enable the establishment of SS reference values for a healthy population, resulting in the possibility to draw conclusions about deviations and related pathologies.

An optimization for postpartum depression risk assessment and preventive intervention strategy based machine learning approaches

BACKGROUND

Postpartum depression (PPD) is one of the most common psychiatric disorders for women after delivery. The establishment of an effective PPD prediction model helps to distinguish high-risk groups, and verifying whether such high-risk groups can benefit from drug intervention is very important for clinical guidance.

METHODS

We collected data of parturients that underwent a cesarean delivery. The Control group was divided into a training cohort and a testing cohort. Six different ML models were constructed and we compared their prediction performance in the testing cohort. For model interpretation, we introduced SHapley Additive exPlanations (SHAP). Then, training cohort, ketamine group and dexmedetomidine (DEX) group were classified as high or low risk for PPD by the model. A 1:1 propensity score matching (PSM) was performed to compare the incidence of PPD between two groups in different risk cohorts.

RESULTS

Extreme gradient enhancement (XGB) had the best recognition effect, with an area under the receiver operating characteristic curve (AUROC) of 0.789 (95 % CI 0.742-0.836) in the training cohort and 0.744 (95 % CI 0.655-0.823) in the testing cohort, respectively. A threshold of 21.5 % PPD risk probability was determined. After PSM, the results showed that the incidence of PPD in the two intervention groups was significantly different from the control group in the high-risk cohort (P < 0.001) but not in the low-risk cohort (P > 0.001).

CONCLUSION

Our study demonstrated that the XGB algorithm provided a more accurate in prediction of PPD risk, and it was beneficial to receive early intervention for the high-risk groups distinguished by the model.

Gestational folic acid supplement prevents vitamin D deficiency-induced depression-like behavior by reversing cortical DNA hypomethylation in adult offspring

Depression is a common mental disorder with an increasing incidence. Several studies have demonstrated that cortical DNA hypomethylation is associated with depression-like behaviors. This study aims to investigate whether maternal vitamin D deficiency (VDD) induces depression-like behaviors and to explore the effects of folic acid supplement on VDD-induced cortical DNA hypomethylation in adult offspring. Female mice were fed with a VDD diet, beginning at 5 weeks of age and throughout pregnancy. Depression-like behaviors were evaluated, and cortical 5-methylcytosine (5mC) content was detected in adult offspring. Results showed that depression-like behaviors were observed in adult offspring of the VDD group. Cortical Ache and Oxtr mRNAs were upregulated in female offspring of the VDD group. Cortical Cpt1a and Htr1b mRNAs were increased in male offspring of the VDD group. Moreover, cortical 5mC content was reduced in offspring of VDD-fed dams. The additional experiment showed that serum folate and cortical S-adenosylmethionine (SAM) contents were decreased in the offspring of the VDD group. Folic acid supplement attenuated VDD-induced SAM depletion and reversed cortical DNA methylation. Moreover, folic acid supplement attenuated VDD-induced upregulation of depression-related genes. In addition, folic acid supplement alleviated maternal VDD-induced depression-like behaviors in adult offspring. These results suggest that maternal VDD induces depression-like behavior in adult offspring by reducing cortical DNA methylation. The gestational folic acid supplement prevents VDD-induced depression-like behavior by reversing cortical DNA hypomethylation in adult offspring.

Application of machine learning in predicting the risk of postpartum depression: A systematic review

BACKGROUND

Postpartum depression (PPD) presents a serious health problem among women and their families. Machine learning (ML) is a rapidly advancing field with increasing utility in predicting PPD risk. We aimed to synthesize and evaluate the quality of studies on application of ML techniques in predicting PPD risk.

METHODS

We conducted a systematic search of eight databases, identifying English and Chinese studies on ML techniques for predicting PPD risk and ML techniques with performance metrics. Quality of the studies involved was evaluated using the Prediction Model Risk of Bias Assessment Tool.

RESULTS

Seventeen studies involving 62 prediction models were included. Supervised learning was the main ML technique employed and the common ML models were support vector machine, random forest and logistic regression. Five studies (30 %) reported both internal and external validation. Two studies involved model translation, but none were tested clinically. All studies showed a high risk of bias, and more than half showed high application risk.

LIMITATIONS

Including Chinese articles slightly reduced the reproducibility of the review. Model performance was not quantitatively analyzed owing to inconsistent metrics and the absence of methods for correlation meta-analysis.

CONCLUSIONS

Researchers have paid more attention to model development than to validation, and few have focused on improvement and innovation. Models for predicting PPD risk continue to emerge. However, few have achieved the acceptable quality standards. Therefore, ML techniques for successfully predicting PPD risk are yet to be deployed in clinical environments.

Machine learning in the prediction of postpartum depression: A review

BACKGROUND

Current screening options in the setting of postpartum depression (PPD) are firmly rooted in self-report symptom-based tools. The implementation of the modern machine learning (ML) approaches might, in this context, represent a way to refine patient screening by precisely identifying possible PPD predictors and, subsequently, a population at risk of developing the disease, in an effort to lower its morbidity, mortality and its economic burden.

METHODS

We performed a bibliographic search on PubMed and Embase looking for studies aimed at the identification of PPD predictors using ML techniques.

RESULTS

Among the 482 articles retrieved, 11 met the inclusion criteria. The most used algorithm was the support vector machine. Notably, all studies reached an area under the curve above 0.7, ultimately suggesting that the prediction of PPD could be feasible. Variables obtained from sociodemographic and clinical aspects (psychiatric and gynecological factors) seem to be the most reliable. Only three studies employed biological variables, in the form of blood, genetic and epigenetic predictors, while no study employed imaging techniques.

LIMITATIONS

The literature on PPD prediction via ML techniques is currently scarce, with most studies employing different variables selection and ML algorithms, ultimately reducing the generalizability of the results.

CONCLUSIONS

The identification of a population at risk of developing PPD might be feasible with current technology and clinical knowledge. Further studies are necessary to clarify how such an approach could be implemented into clinical practice.

Perinatal Obsessive-Compulsive Disorder: Epidemiology, Phenomenology, Etiology, and Treatment

PURPOSE OF REVIEW

We review recent evidence concerning the epidemiology, etiology, and treatment of obsessive-compulsive disorder (OCD) in the perinatal period. We examine studies reporting on rates of both new-onset OCD and exacerbation in both pregnancy and postpartum; explore both biological and psychosocial risk factors for the disorder; and review the latest evidence concerning treatment.

RECENT FINDINGS

Evidence is limited in all areas, with rates of both OCD and subthreshold obsessive-compulsive symptoms varying widely across studies. Prevalence is likely higher in the perinatal period than in the general population. Clinical features in the perinatal period are more likely than at other times to concern harm to the child, with contamination and aggressive obsessions and cleaning and checking compulsions especially common. Research into the biological etiology is too limited at this time to be definitive. Both observational and randomized controlled trials support cognitive behavioral therapy with exposure and response prevention (CBT with ERP) as a first-line treatment, with limited evidence also supporting the use of selective serotonin reuptake inhibitors (SSRIs). Treatment considerations in the perinatal period must weigh the risks of treatment vs. the risks of untreated illness. Perinatal OCD is common and can be impairing. Clinical features differ somewhat compared to non-perinatal periods. Treatment does not differ from that used in the general population, though evidence pertaining specifically to the perinatal period is sparse.

Exposure to environmental chemicals and perinatal psychopathology

Women are nearly twice as likely to develop mood disorders compared with men, and incidence is greatest during reproductive transitions, including pregnancy and postpartum. Because these periods are characterized by dramatic hormonal and physiologic changes, there is heightened susceptibility to external factors, such as exposure to environmental toxicants, which may play a role in maternal psychopathology. The purpose of this scoping review was to provide an overview of studies conducted in humans and animal models on the effects of nonoccupational exposure to environmental chemicals on maternal psychopathology during the perinatal period. The largest number of studies examined exposure to environmental tobacco smoke and antenatal depression and showed consistently positive findings, although more prospective studies using biomarkers for exposure assessment are needed. The few studies examining persistent organic pollutants such as polybrominated diphenyl ethers and perinatal depression were consistent in showing associations with increased depressive symptoms. Results were mixed for exposure to heavy metals and non-persistent chemicals, but a strong literature in animal models supported an association between bisphenols and phthalates and reduced maternal behavior and care of pups after parturition. Biological mechanisms may include endocrine disruption, neurotransmitter system impairment, alterations in gene expression, and immune activation and inflammation. Additional longitudinal studies that include biospecimen collection are essential to furthering the understanding of how environmental toxicants during pregnancy may affect perinatal psychopathology and the underlying mechanisms of action. Future work should also leverage the parallels between animal and human maternal behavior, thereby highlighting the opportunity for multidisciplinary work in this avenue.

Conducting epigenetics research with refugees and asylum seekers: attending to the ethical challenges

An increase in global violence has forced the displacement of more than 70 million people, including 26 million refugees and 3.5 asylum seekers. Refugees and asylum seekers face serious socioeconomic and healthcare barriers and are therefore particularly vulnerable to physical and mental health risks, which are sometimes exacerbated by immigration policies and local social discriminations. Calls for a strong evidence base for humanitarian action have encouraged conducting research to address the barriers and needs of refugees and asylum seekers. Given the role of epigenetics factors to mediate the effect of psychological and environmental exposures, epigenetic modifications have been used as biomarkers for life adversity and disease states. Therefore, epigenetic research can be potentially beneficial to address some of the issues associated with refugees and asylum seekers. Here, we review the value of previous and ongoing epigenetic studies with traumatized populations, explore some of the ethical challenges associated with epigenetic research with refugees and asylees and offer suggestions to address or mitigate some of these challenges. Researchers have an ethical responsibility to implement strategies to minimize the harms and maximize the short and long-term benefits to refugee and asylee participants.

Evaluating brexanolone for the treatment of postpartum depression

INTRODUCTION

Postpartum depression (PPD) is a serious and common complication of childbirth that can have deleterious effects not only on the mother but on the cognitive and behavioral development of exposed children. Brexanolone is a novel, soluble synthetic formulation of the natural hormone allopregnanolone and acts as a positive allosteric modulator of the gamma-aminobutyric acid A receptor (GABAA). Allopregnanolone levels dramatically decrease during the postpartum time-period and some studies indicate lower serum levels of allopregnanolone during pregnancy in women that go on to develop PPD.Areas covered: The author provides an overview of brexanolone as a treatment option for PPD including coverage of its pharmacokinetics, efficacy, safety, and tolerability. Furthermore, the author gives her expert perspectives on its use and its standing in the treatment armamentarium moving forward.Expert opinion: Brexanolone represents a breakthrough for psychiatry due to its novel mechanism of action, its rapid onset of action, and its sustained effects without continued administration. It is appropriate for use in women with moderate to severe PPD. Experience with the medication and further research is needed to clarify whether the current recommended dosing regimen is required for efficacy.

Developmental cannabidiol exposure increases anxiety and modifies genome-wide brain DNA methylation in adult female mice

BACKGROUND

Use of cannabidiol (CBD), the primary non-psychoactive compound found in cannabis, has recently risen dramatically, while relatively little is known about the underlying molecular mechanisms of its effects. Previous work indicates that direct CBD exposure strongly impacts the brain, with anxiolytic, antidepressant, antipsychotic, and other effects being observed in animal and human studies. The epigenome, particularly DNA methylation, is responsive to environmental input and can direct persistent patterns of gene regulation impacting phenotype. Epigenetic perturbation is particularly impactful during embryogenesis, when exogenous exposures can disrupt critical resetting of epigenetic marks and impart phenotypic effects lasting into adulthood. The impact of prenatal CBD exposure has not been evaluated; however, studies using the psychomimetic cannabinoid Δ9-tetrahydrocannabinol (THC) have identified detrimental effects on psychological outcomes in developmentally exposed adult offspring. We hypothesized that developmental CBD exposure would have similar negative effects on behavior mediated in part by the epigenome. Nulliparous female wild-type Agouti viable yellow (Avy) mice were exposed to 20 mg/kg CBD or vehicle daily from two weeks prior to mating through gestation and lactation. Coat color shifts, a readout of DNA methylation at the Agouti locus in this strain, were measured in F1 Avy/a offspring. Young adult F1 a/a offspring were then subjected to tests of working spatial memory and anxiety/compulsive behavior. Reduced-representation bisulfite sequencing was performed on both F0 and F1 cerebral cortex and F1 hippocampus to identify genome-wide changes in DNA methylation for direct and developmental exposure, respectively.

RESULTS

F1 offspring exposed to CBD during development exhibited increased anxiety and improved memory behavior in a sex-specific manner. Further, while no significant coat color shift was observed in Avy/a offspring, thousands of differentially methylated loci (DMLs) were identified in both brain regions with functional enrichment for neurogenesis, substance use phenotypes, and other psychologically relevant terms.

CONCLUSIONS

These findings demonstrate for the first time that despite positive effects of direct exposure, developmental CBD is associated with mixed behavioral outcomes and perturbation of the brain epigenome.

A new molecular risk pathway for postpartum mood disorders: clues from steroid sulfatase-deficient individuals

Postpartum mood disorders develop shortly after childbirth in a significant proportion of women. These conditions are associated with a range of symptoms including abnormally high or low mood, irritability, cognitive disorganisation, disrupted sleep, hallucinations/delusions, and occasionally suicidal or infanticidal ideation; if not treated promptly, they can substantially impact upon the mother's health, mother-infant bonding, and family dynamics. The biological precipitants of such disorders remain unclear, although large changes in maternal immune and hormonal physiology following childbirth are likely to play a role. Pharmacological therapies for postpartum mood disorders can be effective, but may be associated with side effects, concerns relating to breastfeeding, and teratogenicity risks when used prophylactically. Furthermore, most of the drugs that are used to treat postpartum mood disorders are the same ones that are used to treat mood episodes during non-postpartum periods. A better understanding of the biological factors predisposing to postpartum mood disorders would allow for rational drug development, and the identification of predictive biomarkers to ensure that 'at risk' mothers receive earlier and more effective clinical management. We describe new findings relating to the role of the enzyme steroid sulfatase in maternal postpartum behavioural processes, and discuss how these point to a novel molecular risk pathway underlying postpartum mood disorders. Specifically, we suggest that aberrant steroid hormone-dependent regulation of neuronal calcium influx via extracellular matrix proteins and membrane receptors involved in responding to the cell's microenvironment might be important. Testing of this hypothesis might identify novel therapeutic targets and predictive biomarkers.

Postpartum Depression: Current Status and Possible Identification Using Biomarkers

Postpartum depression (PPD) is a serious health issue that can affect about 15% of the female population within after giving birth. It often conveys significant negative consequences to the offsprings. The symptoms and risk factors are somewhat similar to those found in non-postpartum depression. The main difference resides in the fact that PPD is triggered by postpartum specific factors, including especially biological changes in the hormone levels. Patients are usually diagnosed using a questionnaire onsite or in a clinic. Treatment of PPD often involves psychotherapy and antidepressant medications. In recent years, there have been more researches on the identification of biological markers for PPD. In this review, we will focus on the current research status of PPD, with an emphasis on the recent progress made on the identification of PPD biomarkers.

The hypothalamic-pituitary-adrenal axis in the perinatal period: Its relationship with major depressive disorder and early life adversity

Objectives: Effects of major depressive disorder and early life adversity (ELA) on the maternal HPA axis in the perinatal period were examined.Methods: Four groups of women (n = 127) were recruited, with the perinatal groups being compared during pregnancy (Preg) and at two months postpartum (PP) - [1] Depressed during pregnancy (Depressed-Preg/PP), [2] Prior history of depression but euthymic during pregnancy (History-Preg/PP), [3] Healthy pregnant women (Control-Preg/PP), and [4] Healthy non-pregnant women (Non-pregnant Control). Serial saliva samples were collected over the course of a day and waking and evening cortisol, total cortisol output and the cortisol awakening response were examined.Results: There were no HPA axis differences among the three groups during pregnancy. A history of ELA, regardless of comorbid depression, was associated with higher evening cortisol levels during pregnancy (p = 0.015). Women in the Depressed-PP group had had higher evening cortisol levels compared to the History-PP group (p < 0.017).Conclusions: Evening cortisol measures are a potential marker for both ELA and depression, with higher levels during pregnancy being associated with ELA and higher levels postpartum being associated with antenatal depression.