Antidepressant effects of esketamine via the BDNF/AKT/mTOR pathway in mice with postpartum depression and their offspring

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.

TOM40 mediates the effect of TSPO on postpartum depression partially through regulating calcium homeostasis in microglia

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.

Intrinsically dysregulated cellular stress signaling genes and gene networks in postpartum depression

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.

Transcriptome-wide association study for postpartum depression implicates altered B-cell activation and insulin resistance

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.

The combination of fluoxetine and environmental enrichment reduces postpartum stress-related behaviors through the oxytocinergic system and HPA axis in mice

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.

Changes in salivary oxytocin levels and bonding disorder in women from late pregnancy to early postpartum: A pilot study

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.

Polygenic risk for circulating reproductive hormone levels and their influence on hippocampal volume and depression susceptibility

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.

Pharmacotherapy of Postpartum Depression: Current Approaches and Novel Drug Development

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.

Maternal circadian cortisol mediates the link between prenatal distress and breastfeeding

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.

Pathophysiological mechanisms implicated in postpartum depression

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.

The HPA Axis During the Perinatal Period: Implications for Perinatal Depression

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.

Neuroactive Steroids and Perinatal Depression: a Review of Recent Literature

PURPOSE OF REVIEW

The purpose of this review is to provide a theoretical explanation and a review of the recent literature concerning the role of neuroactive steroids in perinatal depression, and to use this information to suggest future directions of research.

RECENT FINDINGS

The bulk of the evidence on neuroactive steroids in perinatal depression concerns allopregnanolone. Recent studies have been mixed, with some studies finding a direct correlation between lower levels of allopregnanolone and increased depressive symptoms but other studies finding no relationship. Evidence concerning other neuroactive steroids and perinatal depression is sparse. Additional research is needed with larger sample sizes and better characterization across the perinatal period (rather than cross-sectionally). Because some studies point to a lag between neuroactive steroid dysregulation and subsequent symptoms, future research should consider interactions with other aspects of neuroactive steroid physiology, such as synthetic enzymes or receptor plasticity.

The role of tryptophan metabolism in postpartum depression

The Postpartum depression (PPD) is the most common postpartum psychiatric disorder, afflicting approximately 10%-20% of new mothers. Clinical symptoms of the PPD include depressive disorder, agitation, insomnia, anxiety and confusion, resulting in an increase in suicidal tendencies, thereby having significant impacts on the puerpera, newborn and their family. A growing body of data indicate a role for alterations in tryptophan metabolism in the PPD. The metabolism of tryptophan produces an array of crucial factors that can differentially regulate key physiological processes linked to the PPD. Importantly, an increase in stress hormones and immune-inflammatory activity drives tryptophan to the production of neuroregulatory kynurenine pathway products and away from the serotonin and melatonin pathways. This links the PPD to other disorders of depressed mood, which are classically associated with decreased serotonin and melatonin, coupled to increases in kynurenine pathway products. Several kynurenine pathway products, such as kynurenic acid and quinolinic acid, can have neuroregulatory effects, with consequences pathological underpinnings of the PPD. The current article reviews the role of alterations in tryptophan metabolism in the PPD.

Inability to suppress the stress-induced activation of the HPA axis during the peripartum period engenders deficits in postpartum behaviors in mice

The stress-induced activation of the hypothalamic-pituitary-adrenal (HPA) axis is normally suppressed during pregnancy. Dysregulation of the HPA axis has been proposed to play a role in postpartum depression. However, direct investigation into the relationship between the HPA axis and postpartum depression has been hindered by the lack of useful animal models. Building on our discovery of a role for the K+/Cl-co-transporter, KCC2, in the GABAergic regulation of CRH neurons in the paraventricular nucleus of the hypothalamus (PVN), critical for mounting the body's physiological response to stress, we assessed the role of KCC2 in the regulation of the HPA axis during pregnancy and the postpartum period. Here we demonstrate that the normal suppression of the stress-induced activation of the HPA axis during the peripartum period involves maintenance of KCC2 in the PVN. Mice lacking KCC2 specifically in corticosterone-releasing hormone (CRH) neurons, which govern the activity of the HPA axis (KCC2/Crh mice), exhibit dysregulation of the HPA axis and abnormal postpartum behaviors. Loss of KCC2 specifically in CRH neurons in the PVN is sufficient to reproduce the depression-like phenotype and deficits in maternal behaviors during the postpartum period. Similarly, chemogenetic activation of CRH neurons in the PVN is sufficient to induce abnormal postpartum behaviors and chemogenetic silencing of CRH neurons in the PVN can ameliorate abnormal postpartum behaviors observed in KCC2/Crh mice. This study demonstrates that dysregulation of the HPA axis is sufficient to induce abnormal postpartum behaviors and deficits in maternal behaviors in mice, providing empirical support for a role of HPA axis dysfunction in the pathophysiology of postpartum depression.

High paternal testosterone may protect against postpartum depressive symptoms in fathers, but confer risk to mothers and children

Following the birth of an infant, decreases in testosterone and increases in depressive symptoms have been observed in fathers. Paternal testosterone may reflect fathers' investment in pair-bonding and paternal caregiving and, as such, may be associated with maternal and familial well-being. This study tests associations between paternal testosterone, paternal and maternal postpartum depressive symptoms, and subsequent family functioning. Within 149 couples, fathers provided testosterone samples when infants were approximately nine months old and both parents reported on postpartum depressive symptoms at two, nine, and 15months postpartum. Fathers with lower aggregate testosterone reported more depressive symptoms at two and nine months postpartum. Mothers whose partners had higher evening testosterone reported more depressive symptoms at nine and 15months postpartum. Maternal relationship satisfaction mediated this effect, such that mothers with higher testosterone partners reported more relationship dissatisfaction, which in turn predicted more maternal depressive symptoms. Higher paternal testosterone and paternal depressive symptoms at nine months postpartum each independently predicted greater fathering stress at 15months postpartum. Higher paternal testosterone also predicted more mother-reported intimate partner aggression at 15months postpartum. In addition to linear relationships between testosterone and depression, curvilinear relationships emerged such that fathers with both low and high testosterone at nine months postpartum reported more subsequent (15-month) depressive symptoms and fathering stress. In conclusion, whereas higher paternal testosterone may protect against paternal depression, it contributed to maternal distress and suboptimal family outcomes in our sample. Interventions that supplement or alter men's testosterone may have unintended consequences for family well-being.

Allopregnanolone levels and depressive symptoms during pregnancy in relation to single nucleotide polymorphisms in the allopregnanolone synthesis pathway

Allopregnanolone, a neurosteroid whose levels rise throughout gestation, putatively stabilizes antenatal mood. The present study aimed to investigate associations of plasma allopregnanolone to antenatal depressive symptoms, as well as to genetic and obstetric factors. Allopregnanolone plasma levels from 284 pregnant women were measured around gestational week 18. Haplotype tag single nucleotide polymorphisms in the aldo-keto reductase family 1, members C2 and C4 (AKR1C2, AKR1C4), and steroid 5 alpha-reductase 1 and 2 (SRD5A1, and SRD5A2) genes were genotyped in a larger sample of pregnant women (n=1351). The Edinburgh Postnatal Depression Scale (EPDS) was administered via web-questionnaires in gestational weeks 17 and 32. Demographic and obstetric data was retrieved from web-questionnaires and medical records. There was no association between allopregnanolone levels and depressive symptoms. Furthermore, no associations between allopregnanolone level and synthesis pathway genotypes were found after accounting for multiple comparisons. However, exploratory analyses suggested that the women who were homozygous for the minor allele of the AKR1C2 polymorphism rs1937863 had nominally lower allopregnanolone levels and lower depression scores in gestational week 17, but also the highest increase in depression scores between week 17 and 32. Additionally, higher body mass index was associated with lower allopregnanolone levels. The results do not support second trimester plasma allopregnanolone as a mood stabilizing factor. However, we speculate that AKR1C2 variation may alter the susceptibility to depressive symptoms through effects on central allopregnanolone synthesis. Another implication of this study is that the relationship between neuroactive steroids and obesity in pregnancy deserves to be investigated.

Glutamatergic and neural dysfunction in postpartum depression using magnetic resonance spectroscopy

Although postpartum depression (PPD) is a prevalent subtype of major depressive disorder, neuroimaging studies on PPD are rare, particularly those identifying neurochemical abnormalities obtained by proton magnetic resonance spectroscopy (¹H-MRS). The dorsolateral prefrontal (DLPF) and the anterior cingulate gyrus (ACG) are part of the neural pathways involved in executive functions and emotional processing, and both structures have been implicated in the neurobiology of depressive disorders. This study aimed to evaluate brain metabolites abnormalities in women with PPD compared with healthy postpartum (HP) women. Thirty-six PPD (34 without antidepressants) and 25 HP women underwent a ¹H-MRS acquired on a 3-T MRI system, with the volume of interest positioned in ACG and DLPF. An ANCOVA was conducted with age, postpartum time, and contraceptive type as covariates. PPD group presented significantly lower Glutamate+Glutamine (Glx, -0.95mM) and N-acetylaspartate+N-acetylaspartylglutamate (NAA, -0.60mM) values in DLPF. There were no significant differences between groups in ACG, but we found a significant increase of Glutamate (Glu, 2.18mM) and Glx (1.84mM) in participants using progestogen-only contraceptives. These findings suggest glutamatergic dysfunction and neuronal damage in the DLPF of PPD patients, similarly to other subtypes of depressive disorders. Progestogens seem to interfere in the neurochemistry of ACG.

Activation of Sigma-1 Receptor Alleviates Postpartum Estrogen Withdrawal-Induced "Depression" Through Restoring Hippocampal nNOS-NO-CREB Activities in Mice

Postpartum depression affects approximately 15 % of mothers; however, its pathological mechanisms still remain unclear. Ovariectomized adult mice received the administration of estrogen (E2) and progesterone with a subsequent alone E2, termed hormone-simulated pregnancy (HSP). Affective behaviors as assessed by forced swim and tail suspension tests, hippocampal neuronal nitric oxide synthase (nNOS), nitric oxide (NO), cyclic AMP (cAMP) response element binding protein (CREB) phosphorylation (phosphor-CREB), and neurosteroidogenesis were examined before E2 withdrawal (EW; HSP mice) and on days 2-4 (early-EW mice) and days 8-10 (late-EW mice) after EW. Depressive-like behaviors were observed in early-EW mice but not in late-EW mice. Levels of nNOS, NO, and phosphor-CREB were increased in HSP mice followed by a significant decline in early-EW mice with a subsequent restoration in late-EW mice. The treatment of early-EW mice with NO donor alleviated depressive-like behaviors and decline of phosphor-CREB. The nNOS inhibitor and NO scavenger caused depressive-like behaviors and reduced phosphor-CREB in HSP mice and late-EW mice. Notably, the levels of steroidogenic enzymes StAR and P450scc were elevated in late-EW mice. The sigma-1 receptor (σ1R) agonist could alleviate depressive-like behaviors and decline of nNOS-NO-CREB in early-EW mice. The pharmacological blockade or deficiency of σ1R in late-EW mice caused depressive-like behaviors with decline of nNOS-NO-CREB. The reduction of hippocampal brain-derived neurotrophic factor (BDNF) or N-methyl-D-aspartic acid (NMDA) receptor NR2B phosphorylation in early-EW mice could recover in late-EW mice, which was sensitive to the blockade of σ1R. The NMDA receptor agonist, but not TrkB receptor activator, could correct the decline of nNOS-NO-CREB in early-EW mice. The findings indicate that the activation of σ1R can alleviate postpartum "depression" through increasing nNOS-NO-CREB activities.

Brain neurotransmitters in an animal model with postpartum depressive-like behavior

Post-Partum Depression (PPD) occurs in 15% of pregnancies and its patho-physiology is not known. We studied female BALB/c ("depressive") and C57BL/6 (control) mice as a model for PPD and assessed their behavior and correlates with brain neurotransmitters (NTs) - norepinephrine, dopamine, serotonin and intermediates, during the pre-pregnancy (PREP), pregnancy (PREG) and post-partum (PP) periods. Depressive-like behavior was evaluated by the Open Field (OFT), Tail Suspension (TST) and Forced Swim (FST) tests. Neurotransmitters (NTs) were determined in the striatum (care-giving), hippocampus (cognitive function) and hypothalamus (maternal care & eating behavior). In the BALB/c mice, while their performance in all behavioral tests was significantly reduced during pregnancy and P-P indicative of the development of depressive-like responses, no changes were observed in the C57BL/6 mice. Changes in NTs in BALB/C were as follows: PREP, all NTs in the three brain areas were decreased, although an increase in dopamine release was observed in the hippocampus. PREG: No changes were observed in the NTs except for a decrease in 5-HT in the striatum. P-P: striatum, low 5-HT, NE and dopamine; Hippocampus: low 5-HT, NE and high Dopamine; hypothalamus: all NTs increased, especially NE. Following pregnancy and delivery, the BALB/c mice developed depressive-like behavior associated with a significant decrease in 5-HT, dopamine and NE in the striatum and 5-HT and NE in the hippocampus. Dopamine increased in the latter together with a significant increase in all NTs in the hypothalamus. These findings suggest that the development of PPD may be associated with NT changes. Normalization of these alterations may have a role in the treatment of PPD.

Stress induces equivalent remodeling of hippocampal spine synapses in a simulated postpartum environment and in a female rat model of major depression

Stress and withdrawal of female reproductive hormones are known risk factors of postpartum depression. Although both of these factors are capable of powerfully modulating neuronal plasticity, there is no direct electron microscopic evidence of hippocampal spine synapse remodeling in postpartum depression. To address this issue, hormonal conditions of pregnancy and postpartum period were simulated in ovariectomized adult female Sprague-Dawley rats (n=76). The number of hippocampal spine synapses and the depressive behavior of rats in an active escape task were investigated in untreated control, hormone-withdrawn 'postpartum', simulated proestrus, and hormone-treated 'postpartum' animals. After 'postpartum' withdrawal of gonadal steroids, inescapable stress caused a loss of hippocampal spine synapses, which was related to poor escape performance in hormone-withdrawn 'postpartum' females. These responses were equivalent with the changes observed in untreated controls that is an established animal model of major depression. Maintaining proestrus levels of ovarian hormones during 'postpartum' stress exposure did not affect synaptic and behavioral responses to inescapable stress in simulated proestrus animals. By contrast, maintaining pregnancy levels of estradiol and progesterone during 'postpartum' stress exposure completely prevented the stress-induced loss of hippocampal spine synapses, which was associated with improved escape performance in hormone-treated 'postpartum' females. This protective effect appears to be mediated by a muted stress response as measured by serum corticosterone concentrations. In line with our emerging 'synaptogenic hypothesis' of depression, the loss of hippocampal spine synapses may be a novel perspective both in the pathomechanism and in the clinical management of postpartum affective illness.

Integrated theory to unify status among schizophrenia and manic depressive illness

Tryptophan hydroxylase 1 is primarily expressed in the gastrointestinal tract, and has been associated with both schizophrenia and depression. Although decreased serotonin activity has been reported in both depression and mania, it is important to investigate the interaction between serotonin and other neurotransmitter systems. There are competitive relationships between branched-chain amino acids, and tryptophan and tyrosine that relate to physical activity, and between L-3,4-dihydroxyphenylalanine (L-DOPA) and 5-hydroxytryptophan (5-HTP), both highly dependent on intracellular tetrahydrobiopterin concentrations. Here, I propose a chaos theory for schizophrenia, mania, and depression using the competitive interaction between tryptophan and tyrosine with regard to the blood-brain barrier and coenzyme tetrahydrobiopterin. Mania may be due to the initial conditions of physical hyperactivity and hypofunctional 5-HTP-producing cells inducing increased dopamine. Depression may be due to the initial conditions of physical hypoactivity and hypofunctional 5-HTP-producing cells inducing decreased serotonin. Psychomotor excitation may be due to the initial conditions of physical hyperactivity and hyperfunctional 5-HTP-producing cells inducing increased serotonin and substantially increased dopamine. The hallucinatory-paranoid state may be due to the initial conditions of physical hypoactivity and hyperfunctional 5-HTP-producing cells inducing increased serotonin and dopamine.

Prenatal and Postpartum Evening Salivary Cortisol Levels in Association with Peripartum Depressive Symptoms

BACKGROUND

The biology of peripartum depression remains unclear, with altered stress and the Hypothalamus-Pituitary-Adrenal axis response having been implicated in its pathophysiology.

METHODS

The current study was undertaken as a part of the BASIC project (Biology, Affect, Stress, Imaging, Cognition), a population-based longitudinal study of psychological wellbeing during pregnancy and the postpartum period in Uppsala County, Sweden, in order to assess the association between evening salivary cortisol levels and depressive symptoms in the peripartum period. Three hundred and sixty-five pregnant women from the BASIC cohort were recruited at pregnancy week 18 and instructed to complete a Swedish validated version of the Edinburgh Postnatal Depression Scale at the 36th week of pregnancy as well as the sixth week after delivery. At both times, they were also asked to provide evening salivary samples for cortisol analysis. A comprehensive review of the relevant literature is also provided.

RESULTS

Women with postpartum EPDS score ≥ 10 had higher salivary evening cortisol at six weeks postpartum compared to healthy controls (median cortisol 1.19 vs 0.89 nmol/L). A logistic regression model showed a positive association between cortisol levels and depressive symptoms postpartum (OR = 4.1; 95% CI 1.7-9.7). This association remained significant even after controlling for history of depression, use of tobacco, partner support, breastfeeding, stressful life events, and sleep problems, as possible confounders (aOR = 4.5; 95% CI 1.5-14.1). Additionally, women with postpartum depressive symptoms had higher postpartum cortisol levels compared to both women with depressive symptoms antenatally and controls (p = 0.019 and p = 0.004, respectively).

CONCLUSIONS

Women with depressive symptoms postpartum had higher postpartum cortisol levels, indicating an altered response of the HPA-axis in postpartum depression.

Early life social stress induced changes in depression and anxiety associated neural pathways which are correlated with impaired maternal care

Exposures to various types of early life stress can be robust predictors of the development of psychiatric disorders, including depression and anxiety. The objective of the current study was to investigate the roles of the translationally relevant targets of central vasopressin, oxytocin, ghrelin, orexin, glucocorticoid, and the brain-derived neurotrophic factor (BDNF) pathway in an early chronic social stress (ECSS) based rodent model of postpartum depression and anxiety. The present study reports novel changes in gene expression and extracellular signal related kinase (ERK) protein levels in the brains of ECSS exposed rat dams that display previously reported depressed maternal care and increased maternal anxiety. Decreases in oxytocin, orexin, and ERK proteins, increases in ghrelin receptor, glucocorticoid and mineralocorticoid receptor mRNA levels, and bidirectional changes in vasopressin underscore related work on the adverse long-term effects of early life stress on neural activity and plasticity, maternal behavior, responses to stress, and depression and anxiety-related behavior. The differences in gene and protein expression and robust correlations between expression and maternal care and anxiety support increased focus on these targets in animal and clinical studies of the adverse effects of early life stress, especially those focusing on depression and anxiety in mothers and the transgenerational effects of these disorders on offspring.

Oxytocin and HPA stress axis reactivity in postpartum women

BACKGROUND

Lactation is thought to buffer stress reactivity via oxytocin (OT). Dysregulation of the HPA axis has been reported in women with postpartum depression (PPD). The co-occurrence of PPD and lactation failure suggests that abnormalities in OT signaling may play a role in PPD. We hypothesized that abnormal OT signaling is implicated in dysregulated HPA axis reactivity among postpartum women with mood symptoms. In a prospective perinatal cohort, we tested associations between OT levels during breastfeeding and stress reactivity.

METHODS

We recruited 52 pregnant women who intended to breastfeed, among whom 47 underwent a standardized stressor, the Trier Social Stress Test (TSST), at 8 weeks postpartum. 39 were breastfeeding at time of TSST. We assessed mood symptoms using validated instruments and defined as symptomatic women with EPDS ≥ 10 and/or Spielberger ≥ 34. Following IV placement for blood draws, women breastfed their infants and then underwent the TSST. Mothers' hormone responses were quantified.

RESULTS

Among symptomatic breastfeeding women (N=11; asymptomatic N=28), we found lower OT levels during breastfeeding (p<0.05) and higher CORT levels (p<0.05) both during breastfeeding and the TSST, as compared to asymptomatic breastfeeding women. In a mixed effects model examining CORT reactivity by symptom group and OT AUC, we observed a paradoxical response in symptomatic breastfeeding women during the TSST (group × time × OT AUC p<0.05); higher OT AUC was associated with higher CORT.

CONCLUSIONS

In all breastfeeding women, the surge of OT during feeding appears to buffer subsequent stress-induced CORT secretion. However, in symptomatic breastfeeding women, we found a positive correlation between OT AUC and CORT, instead of the expected negative correlation, which we found among asymptomatic women.

Serotonin deficiency alters susceptibility to the long-term consequences of adverse early life experience

Brain 5-HT deficiency has long been implicated in psychiatric disease, but the effects of 5-HT deficiency on stress susceptibility remain largely unknown. Early life stress (ELS) has been suggested to contribute to adult psychopathology, but efforts to study the long-term consequences of ELS have been limited by a lack of appropriate preclinical models. Here, we evaluated the effects of 5-HT deficiency on several long-term cellular, molecular, and behavioral responses of mice to a new model of ELS that combines early-life maternal separation (MS) of pups and postpartum learned helplessness (LH) training in dams. Our data demonstrate that this paradigm (LH/MS) induces depressive-like behavior and impairs pup retrieval in dams. In addition, we show that brain 5-HT deficiency exacerbates anxiety-like behavior induced by LH/MS and blunts the effects of LH/MS on acoustic startle responses in adult offspring. Although the mechanisms underlying these effects remain unclear, following LH/MS, 5-HT-deficient animals had significantly less mRNA expression of the mineralocorticoid receptor in the amygdala than wild-type animals. In addition, 5-HT-deficient mice exhibited reduced mRNA levels of the 5-HT2a receptor and p11 in the hippocampus regardless of stress. LH/MS decreased the number of doublecortin+ immature neurons in the hippocampus in both wild-type (WT) and 5-HT-deficient animals. Our data emphasize the importance of complex interactions between genetic factors and early life experience in mediating long-term changes in emotional behavior. These findings may have important implications for our understanding of the combinatorial roles of 5-HT deficiency, ELS, and postpartum depression in the development of neuropsychiatric disorders.

Early predictive biomarkers for postpartum depression point to a role for estrogen receptor signaling

BACKGROUND

Postpartum depression (PPD) affects approximately 13% of women and has a negative impact on mother and infant, hence reliable biological tests for early detection of PPD are essential. We aimed to identify robust predictive biomarkers for PPD using peripheral blood gene expression profiles in a hypothesis-free genome-wide study in a high-risk, longitudinal cohort.

METHOD

We performed a genome-wide association study in a longitudinal discovery cohort comprising 62 women with psychopathology. Gene expression and hormones were measured in the first and third pregnancy trimesters and early postpartum (201 samples). The replication cohort comprised 24 women with third pregnancy trimester gene expression measures. Gene expression was measured on Illumina-Human HT12 v4 microarrays. Plasma estradiol and estriol were measured. Statistical analysis was performed in R.

RESULTS

We identified 116 transcripts differentially expressed between the PPD and euthymic women during the third trimester that allowed prediction of PPD with an accuracy of 88% in both discovery and replication cohorts. Within these transcripts, significant enrichment of transcripts implicated that estrogen signaling was observed and such enrichment was also evident when analysing published gene expression data predicting PPD from a non-risk cohort. While plasma estrogen levels were not different across groups, women with PPD displayed an increased sensitivity to estrogen signaling, confirming the previously proposed hypothesis of increased sex-steroid sensitivity as a susceptibility factor for PPD.

CONCLUSIONS

These results suggest that PPD can be robustly predicted in currently euthymic women as early as the third trimester and these findings have implications for predictive testing of high-risk women and prevention and treatment for PPD.

Psychosocial stress moderates the relationships between oxytocin, perinatal depression, and maternal behavior

The hormone oxytocin (OT) is of particular interest in the study of childbearing women, as it has a role in the onset and course of labor and breastfeeding. Recent research has linked OT to maternal caregiving behavior towards her infant, and to postpartum depressive symptomatology. There is also evidence that psychosocial adversity affects the oxytocin system. The present study investigated the relationship of endogenous OT in women during pregnancy and at 8weeks postpartum to psychosocial stress, maternal symptoms of depression, and maternal sensitive behavior. It was hypothesized that OT would mediate the effects of maternal depressive symptoms on maternal interactive behavior. We also tested the hypothesis that psychosocial stress would moderate the relationship between OT and maternal depressive symptoms and sensitive behavior. A community sample of 287 women was assessed at 12-14weeks of gestation, 32-34weeks of gestation, and 7-9weeks postpartum. We measured plasma OT, maternal symptoms of depression and psychosocial stress. At the postpartum home visit, maternal behavior in interaction with the infant was videotaped, and then coded to assess sensitivity. In the sample as a whole, OT was not related to maternal depressive symptoms or to sensitive maternal behavior. However, among women who reported high levels of psychosocial stress, higher levels of plasma OT were associated with fewer depressive symptoms and more sensitive maternal behavior. These results suggest that endogenous OT may act as a buffer against the deleterious effects of stress, thereby protecting high risk women from developing depressive symptoms and promoting more sensitive maternal interactive behavior.

Prenatal stress, partner support, and infant cortisol reactivity in low-income Mexican American families

Maternal exposure to significant prenatal stress can negatively affect infant neurobiological development and increase the risk for developmental and health disturbances. These effects may be pronounced in low SES and ethnic minority families. We explored prenatal partner support as a buffer of the impact of prenatal stress on cortisol reactivity of infants born to low-income Mexican American women. Women (N=220; age 18-42; 84% Spanish-speaking; 89% foreign born; modal family income $10,000-$15,000) reported on economic stress and satisfaction with spousal/partner support during the prenatal period (26-38 weeks gestation), and infant salivary cortisol reactivity to mildly challenging mother-infant interaction tasks was assessed at women's homes at six weeks postpartum. Multilevel models estimated the interactive effect of prenatal stress and partner support on cortisol reactivity, controlling for covariates and potential confounds. Infants born to mothers who reported high prenatal stress and low partner support exhibited higher cortisol reactivity relative to those whose mothers reported high support or low stress. The effects did not appear to operate through birth outcomes. For low-income Mexican American women, partner support may buffer the impact of prenatal stress on infant cortisol reactivity, potentially promoting more adaptive infant health and development.

Postpartum corticosterone administration reduces dendritic complexity and increases the density of mushroom spines of hippocampal CA3 arbours in dams

Postpartum depression (PPD) affects approximately 15% of mothers after giving birth. A complete understanding of depression during the postpartum period has yet to be established, although disruptions in the hypothalamic-pituitary-adrenal axis and stress during the postpartum may be involved. To model these components in rats, we administered high corticosterone (CORT) postpartum, which increases immobility in the forced swim test (FST), and reduces maternal care, body weight and hippocampal cell proliferation in dams. The hippocampus is altered in response to chronic stress, exposure to high glucocorticoids and in major depression in humans. In the present study, we examined whether high CORT reduced dendritic complexity and spines in the CA3 region of the hippocampus. Additionally, housing complexity was manipulated so that dams and litters were housed either with tubes (complex) or without tubes (impoverished) to investigate the consequences of new animal care regulations. Dams received 40 mg/kg/day of CORT or oil starting on day 2 postpartum for 23 days. Maternal behaviours were assessed on postpartum days 2-8 and dams were tested using the FST on days 21 and 22. Dams were killed on day 24 and brains were processed for Golgi impregnation. Pyramidal cells in the CA3 subfield were traced using a camera lucida and analysed for branch points and dendritic complexity, as well as spine density and type on both basal and apical arbours. As previously established, high CORT postpartum reduced maternal care and increased immobility in the FST, which is a measure of depressive-like behaviour. High CORT postpartum reduced the complexity of basal arbours and increased mushroom spines on both apical and basal dendrites. Housing complexity had no effect on spines of CA3 pyramidal cells but modest effects on cell morphology. These data show that chronic high CORT in postpartum females alters hippocampal morphology and may provide insight regarding the neurobiological consequences of high stress or CORT during the postpartum period, as well as be relevant for postpartum stress or depression.

Reproductive depression

Reproductive depression is the depression in women that is related to the hormonal changes of the menstrual cycle, pregnancy and the menopause and is manifested clinically as premenstrual depression, postnatal depression and climacteric depression. These three components occur in the same vulnerable women in that a woman with depression in the menopausal transition will usually have a history of premenstrual syndrome (PMS; premenstrual dysphoric disorder [PMDD]), would have been in a good mood during pregnancy and then develop postnatal depression. When the periods return the depression becomes cyclical as PMS. These three conditions are effectively treated with transdermal estrogens which should be the first-choice therapy rather than antidepressants. Estrogens can be used together with antidepressants. The critical time to prevent long-term mood problems is the correct treatment of postnatal depression. In women with low energy and libido, often a side effect of antidepressants, the addition of transdermal testosterone is useful. These women with reproductive depression are often progesterone/progestogen intolerant and a smaller dose or duration of progestogen is a necessary compromise. Alternatively a Mirena IUS or rarely a hysterectomy is required.

[Selective D1-receptor antagonist SCH23390 decreases maternal reactions in rats upon acute and chronic injections in postpartum period]

The influence of the D1-receptor antagonist SCH23390 on the maternal behavior of female rats has been studied. It is established that a comparatively high dose of the drug (acute injections) significantly decreases both the locomotor activity and manifestations of the parental care. Lower dosages do not affect the locomotor activity, but still suppress the maternal behavior (after both acute and chronic injections of SCH23390). The obtained results are discussed in terms of the analysis of the maternal motivation mechanisms and the development of the D1-induced postpartum depression.

The role of melatonin in post-partum psychosis and depression associated with bipolar disorder

Recent data has highlighted the association of a bipolar disorder (BD) with an increased risk of post-partum psychosis and depression. It is suggested that genetic- and environmental-induced decrease in the levels of melatonin in BD contributes to post-partum disorders. Melatonin may also have some efficacy in the treatment of BD, especially in decreasing the side-effects associated with lithium and the neuroleptics. It is proposed that the optimization of melatonin levels, perhaps in conjunction with optimized vitamin D3 level, would decrease post-partum psychosis and depression associated with BD.

Prenatal depression effects and interventions: a review

This review covers research on the negative effects of prenatal depression and cortisol on fetal growth, prematurity and low birthweight. Although prenatal depression and cortisol were typically measured at around 20 weeks gestation, other research suggests the stability of depression and cortisol levels across pregnancy. Women with Dysthymia as compared to Major Depression Disorder had higher cortisol levels, and their newborns had lower gestational age and birthweight. The cortisol effects in these studies were unfortunately confounded by low serotonin and low dopamine levels which in themselves could contribute to non-optimal pregnancy outcomes. The negative effects of depression and cortisol were also potentially confounded by comorbid anxiety, by demographic factors including younger age, less education and lower SES of the mothers and by the absence of a partner or a partner who was unhappy about the pregnancy or a partner who was depressed. Substance use (especially caffeine use) was still another risk factor. All of these problems including prenatal depression, elevated cortisol, prematurity and low birthweight and even postpartum depression have been reduced by prenatal massage therapy provided by the women's partners. Massage therapy combined with group interpersonal psychotherapy was also effective for reducing depression and cortisol levels. Several limitations of these studies were noted and suggestions for future research included exploring other predictor variables like progesterone/estriol ratios, immune factors and genetic determinants. Further research is needed both on the potential use of cortisol as a screening measure and the use of other therapies that might reduce prenatal depression and cortisol in the women and prematurity and low birthweight in their infants.

Disturbances in morning cortisol secretion in association with maternal postnatal depression predict subsequent depressive symptomatology in adolescents

BACKGROUND

We have previously reported higher and more variable salivary morning cortisol in 13-year-old adolescents whose mothers were depressed in the postnatal period, compared with control group adolescents whose mothers did not develop postnatal depression (PND). This observation suggested a biological mechanism by which intrafamilial risk for depressive disorder may be transmitted. In the current article, we examined whether the cortisol disturbances observed at 13 years could predict depressive symptomatology in adolescents at 16 years of age.

METHODS

We measured self-reported depressive symptoms in 16-year-old adolescents who had (n = 48) or had not (n = 39) been exposed to postnatal maternal depression and examined their prediction by morning and evening cortisol indices obtained via 10 days of salivary collections at 13 years.

RESULTS

Elevated morning cortisol secretion at 13 years, and particularly the maximum level recorded over 10 days of collection, predicted elevated depressive symptoms at 16 years over and above 13-year depressive symptom levels and other possible confounding factors. Morning cortisol secretion mediated an association between maternal PND and symptomatology in 16-year-old offspring.

CONCLUSIONS

Alterations in steroid secretion observed in association with maternal PND may provide a mechanism by which risk for depression is transmitted from mother to offspring.

Serotonin 1A receptor reductions in postpartum depression: a positron emission tomography study

OBJECTIVE

To measure brain serotonin-1A (5HT1A) receptor binding potential (BP) in healthy and depressed postpartum women.

DESIGN

5HT1A receptor BP was measured with positron emission tomography by using [(11)C]WAY100635 a single time. Multivariate analysis of variance was used to determine depression effects on 5HT1A receptor BP in relevant brain regions.

SETTING

An academic research environment.

PATIENT(S)

Seven postpartum healthy controls and nine postpartum depressed (PD) subjects with perinatal (antepartum or postpartum) depression onset. Of the nine PD subjects, five had unipolar depression, and four had bipolar disorder.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

5HT1A receptor BP.

RESULT(S)

Age, time since delivery, and reproductive hormones did not differ between groups. Postsynaptic 5HT1A receptor binding in postpartum depression was reduced 20%-28% relative to controls, with most significant reductions in anterior cingulate and mesiotemporal cortices.

CONCLUSION(S)

Postsynaptic 5HT1A receptor binding is reduced in PD women by a similar magnitude as has been shown in other depression samples. The postpartum hormonal milieu and the large proportion of bipolar spectrum subjects in the PD group may have accentuated this finding in this small sample. Recognition of this neurobiological deficit in postpartum depression may be useful in the development of treatments and prevention strategies for this disabling disorder.

Maternal stress and behavior modulate relationships between neonatal stress, attention, and basal cortisol at 8 months in preterm infants

There is evidence that the developmental trajectory of cortisol secretion in preterm infants is altered, with elevated basal cortisol levels observed postnatally through at least 18 months corrected age (CA). This alteration is possibly due to neonatal pain-related stress. High cortisol levels might contribute to greater risk of impaired neurodevelopment. Since maternal factors are important for the regulation of infant stress responses, we investigated relationships between infant (neonatal pain-related stress, attention, cortisol) and maternal (stress, interactive behaviors) factors at age 8 months CA. We found that interactive maternal behaviors buffered the relationship between high neonatal pain-related stress exposure and poorer focused attention in mothers who self-reported low concurrent stress. Furthermore, in preterm infants exposed to high concurrent maternal stress and overwhelming interactive maternal behaviors, higher basal cortisol levels were associated with poor focused attention. Overall, these findings suggest that maternal factors can influence the cognitive resilience at 8 months of preterm infants exposed to early life stress.

The HPA axis and perinatal depression: a hypothesis

Episodes of depression and anxiety are as common during pregnancy as postpartum. Some start in pregnancy and resolve postpartum, others are triggered by parturition and some are maintained throughout. In order to determine any biological basis it is important to delineate these different subtypes. During pregnancy, as well as the rise in plasma oestrogen and progesterone there is a very large increase in plasma corticotropin releasing hormone (CRH), and an increase in cortisol. The latter reaches levels found in Cushing's syndrome and major melancholic depression. Levels of all these hormones drop rapidly on parturition.We here suggest that the symptoms of antenatal and postnatal depression may be different, and linked in part with differences in the function of the hypothalamic pituitary adrenal (HPA) axis. There are two subtypes of major depression, melancholic and atypical, with some differences in symptom profile, and these subtypes are associated with opposite changes in the HPA axis. Antenatal depression may be more melancholic and associated with the raised cortisol of pregnancy, whereas postnatal depression may be more atypical, triggered by cortisol withdrawal and associated with reduced cortisol levels. There is evidence that after delivery some women experience mild bipolar II depression, and others experience post traumatic stress disorder. Both of these are associated with atypical depression. It may also be that some women are genetically predisposed to depression of the melancholic type and some to depression of the atypical type. These women may be more or less vulnerable to depression at the different stages of the perinatal period.

Preliminary evidence of reduced occipital GABA concentrations in puerperal women: a 1H-MRS study

RATIONALE

Childbirth is associated with rapid neuroendocrine fluctuations, which are thought to contribute to the phatogenesis of postpartum major depression (PPD).

OBJECTIVES

The aim of this proton magnetic resonance spectroscopy (1H-MRS) study was two-fold; 1) to examine whether puerperium is associated with alterations in occipital cortex gamma-aminobutyric acid (GABA) concentrations and 2) to determine whether such alterations may be more prominent in women with PPD.

MATERIALS AND METHODS

Nine women with PPD, 14 postpartum healthy controls, and ten healthy follicular phase females underwent 1H-MRS at 2.1 Tesla to measure occipital cortex GABA concentrations. Postpartum women were scanned within 6 months of delivery and prior to resumption of menstruation. Healthy non-puerperal controls, drawn from a historical sample, were scanned during the early to mid-follicular phase when ovarian hormone levels would be similar to those found in the puerperium. GABA data were analyzed using analysis of covariance, and regression models were used to explore the relationship between cortical GABA concentrations and blood levels of estradiol, progesterone, and neurosteroids.

RESULTS

Cortical GABA and plasma allopregnanolone (ALLO) concentrations were reduced in both groups of postpartum women, regardless of PPD diagnosis, compared to healthy follicular phase women. There was no correlation between cortical GABA concentrations and estradiol, progesterone, ALLO, or pregnenolone (PREG).

CONCLUSIONS

This study is the first to describe reductions in occipital cortex GABA levels in the postpartum period, a time of increased vulnerability to mood disturbances in women. The concomitant reduction in peripheral ALLO levels provides further evidence of alterations in the balance between cortical excitation and inhibition during the puerperium. Women with PPD may represent a subgroup of women who fail to adequately adapt to this alteration in the neuroendocrine milieu.

Decreased brain tryptophan availability as a partial determinant of post-partum blues

BACKGROUND

The post-partum blues is a transient mood alteration affecting most women a few days after delivery. Its stereotypic pattern of symptoms and time course, peaking on post-partum day 3-5, is suggestive of biological determinants superimposed on psycho-social factors. This study was designed to evaluate the possible role of the serotonin system during this period through assessment of brain tryptophan availability.

METHODS

Blood samples from 50 women were collected just before (D0) and 3 days after (D3) delivery. Based on plasma concentration of tryptophan, amino acids competing with tryptophan for transport across the blood-brain barrier and on their respective affinities for this transporter, a brain tryptophan availability index (BTAI) was calculated and its variation correlated with the intensity of post-partum blues evaluated through the Kennerley and Gath score at D3.

RESULTS

The BTAI showed a -15% decrease between D0 and D3 (p < 0.01, paired t-test). This decrease was not supported by a drop in plasma tryptophan since its level rather increased (+19%). There was no evidence for change in placental indoleamine-2,3-dioxygenase activity since the variation in plasma l-kynurenine (+12%) paralleled the change in tryptophan level. The decreased BTAI appeared the consequence of a dramatic increase in plasma levels of most amino acids, particularly the competitor aminoacids leucine, isoleucine, valine and tyrosine, during the early post-partum. This decrease in brain tryptophan availability was concomitant to the post-partum blues, whose intensity significantly correlated with the amplitude of BTAI variation (Pearson's coefficient -0.283, p < 0.05).

CONCLUSION

This study suggests that generalized, large amplitude metabolic and/or nutritional changes occurring in the early post-partum result in a transient decrease in brain tryptophan availability, partly accounting for the mood alteration referred to as the post-partum blues, a model for the triggering of puerperal mood disorder in vulnerable women.

The role of estrogen therapy in postpartum psychiatric disorders: an update

OBJECTIVES

The aim of this review is to assess and summarize the existing literature data about the efficacy of estrogen replacement therapy (ERT) in preventing and treating postpartum psychiatric disorders.

METHODS

An extensive and unrestrictive computerized search (from 1970 to June 2005) on MEDLINE/PubMed, TOXNET, EMBASE, and Cochrane Databases was conducted with the following search terms: estradiol, estrogen-treatment, hormonal treatment, therapy, postpartum depression, postnatal depression, puerperal depression, postpartum blues, postpartum psychosis, lactation, and breastfeeding.

RESULTS

In assessing available literature information about the role of ERT in preventing and treating puerperal psychiatric diseases, all reviewed studies were found to suffer from severe methodological limitations.

CONCLUSION

Well-designed and strictly focused multicenter trials are warranted in order to firmly establish the effectiveness of ERT in puerperal psychiatric disorders.

Cortisol decreases and serotonin and dopamine increase following massage therapy

In this article the positive effects of massage therapy on biochemistry are reviewed including decreased levels of cortisol and increased levels of serotonin and dopamine. The research reviewed includes studies on depression (including sex abuse and eating disorder studies), pain syndrome studies, research on auto-immune conditions (including asthma and chronic fatigue), immune studies (including HIV and breast cancer), and studies on the reduction of stress on the job, the stress of aging, and pregnancy stress. In studies in which cortisol was assayed either in saliva or in urine, significant decreases were noted in cortisol levels (averaging decreases 31%). In studies in which the activating neurotransmitters (serotonin and dopamine) were assayed in urine, an average increase of 28% was noted for serotonin and an average increase of 31% was noted for dopamine. These studies combined suggest the stress-alleviating effects (decreased cortisol) and the activating effects (increased serotonin and dopamine) of massage therapy on a variety of medical conditions and stressful experiences.

Cyclic estradiol replacement attenuates stress-induced c-Fos expression in the PVN of ovariectomized rats

Estradiol modulates stress reactions in female rats. Several studies showed anxiolytic effects of estradiol in behavioral tests, but the underlying mechanisms are still unclear. The aim of the current study was to explore how estradiol-treated rats respond to acute and chronic stress compared to ovariectomized rats. Ovariectomized rats received vehicle or 17beta-estradiol injections (10 microg/250 g) once every 4 days, which induced alternating high and low plasma 17beta-estradiol levels. Stress was presented by daily exposure to an adverse environment in which the animals received five footshocks for either 3 or 22 days. Under control conditions no differences were observed, but as soon as stress was applied, reactions of ovariectomized and estradiol-treated rats diverged. Both acute and chronic stress increased the c-Fos protein expression in the paraventricular nucleus (PVN) of the hypothalamus. Cyclic estradiol treatment reduced this stress-induced activation of the PVN, an effect that seems to be dependent on the plasma estradiol levels. No differences in stress-induced corticosterone responses were revealed between the treatment groups. An increase in the number of ERbeta-expressing cells in the PVN of ovariectomized and estradiol-treated rats during chronic stress implied increased ERbeta-mediated mechanisms during these conditions. The dampening effect of estradiol on the excessive stress-induced activity in the PVN may be beneficial for the animal in its response to chronic recurrent stress by reducing the output of the PVN.

Measurement of tryptophan, kynurenine and neopterin in women with and without postpartum blues

BACKGROUND

Activation of the tryptophan-degrading enzyme indoleamine (2,3)-dioxygenase was demonstrated to be critically involved in tolerance induction to prevent fetal rejection. Our study was designed to examine alterations of tryptophan and its catabolic product kynurenine in the postpartum period and to compare them to neopterin as an immunological marker.

METHODS

95 healthy women delivering without complications provided blood during labour, and 2 and 4 days after birth. The blood samples were analysed for concentrations of tryptophan, kynurenine and neopterin. Women were asked to perform the Edinburgh Postnatal Depression Scale (EPDS) on days 2 and 4.

RESULTS

In women without blues symptoms (n=86) tryptophan concentrations increased within 2 days after birth, whereas they did not change in women with postpartum blues (n=9; 9.5%). The group difference reached statistical significance (p<0.05). The change of the kynurenine to tryptophan ratio (kyn/trp), which estimates the degree of tryptophan degradation, was also different between the two groups at days 0 and 2 (p<0.05). Neopterin concentrations decreased between days 2 and 4 (p<0.05), but there were no differences between the two groups.

LIMITATIONS

Our study population had a low prevalence of postpartum blues symptoms.

CONCLUSION

Low postpartal mood is associated with continuously low serum tryptophan after delivery due to an increased degradation to kynurenine, but is independent of the postpartal course of neopterin.

Breastfeeding during maternal antidepressant treatment with serotonin reuptake inhibitors: infant exposure, clinical symptoms, and cytochrome p450 genotypes

BACKGROUND

The aims of the study were to quantify the drug exposure in breastfed infants of antidepressant-treated mothers, to identify possible adverse events, and to correlate these variables to maternal and infant drug metabolism-relevant genotypes and milk triglyceride content.

METHOD

The study included 25 lactating women treated with citalopram (N = 9), sertraline (N = 6), paroxetine (N = 6), fluoxetine (N = 1), or venlafaxine (N = 3) and their 26 breastfed infants. Drug concentrations in maternal and infant serum and milk were analyzed using liquid chromotography mass spectrometry methods; milk triglyceride levels were measured with a commercial kit. Cytochrome P450 (CYP) 2D6 and CYP2C19 activity was determined by polymerase chain reaction-based genotyping of the mothers and infants. An infant adverse event questionnaire was completed by the medication-treated mothers as well as by a control group of medication-free breastfeeding mothers of 68 infants.

RESULTS

Sertraline and paroxetine were not detected in any of the drug-exposed infants. The infant serum level of citalopram was either undetectable (N = 4) or low (N = 6). All venlafaxine-exposed infants had measurable drug concentrations. We identified a paroxetine-treated mother and her infant who were both CYP2D6 poor metabolizers, as well as a citalopram-treated mother with CYP2C19 poor metabolizer status, but the serum drug levels of their infants were still either undetectable (paroxetine) or low (citalopram). There was no evidence of adverse events in the drug-exposed infants.

CONCLUSION

Serum drug levels in breastfed infants of antidepressant-treated mothers were undetectable or low. This study adds further evidence to previously published data indicating that breastfeeding should not be generally discouraged in women using serotonin reuptake inhibitor anti-depressants.

Pooled analysis of antidepressant levels in lactating mothers, breast milk, and nursing infants

OBJECTIVE

The available data on antidepressant levels in nursing infants were analyzed in order to calculate average infant drug levels and determine what factors influence plasma drug levels in breast-feeding infants of mothers treated with antidepressants.

METHOD

Electronic searches of MEDLINE, PreMEDLINE, Current Contents, Biological Abstracts, and PsycINFO from 1966 through July 2002 followed by bibliographic searches identified 67 relevant studies (two unpublished). By consensus the authors identified 57 studies of maternal plasma, breast milk, and/or infant plasma antidepressant levels from nursing mother-infant pairs, measured by liquid chromatography.

RESULTS

Infants with recent prenatal exposure and symptomatic infants included in case reports were analyzed separately. Infant plasma levels were standardized against the average maternal level for each drug. The average infant-maternal plasma ratio was calculated for each drug, and correlations of infant plasma level to maternal dose, maternal plasma level, and breast milk level were calculated. Nortriptyline, paroxetine, and sertraline usually produce undetectable infant levels. Of drugs currently used, fluoxetine produces the highest proportion (22%) of infant levels that are elevated above 10% of the average maternal level. Based on smaller numbers, the data on citalopram indicate that it produces elevated levels in 17% of infants. The milk-to-plasma ratios for 11 antidepressants had a statistically significant negative association with the percentage of the drug bound to protein.

CONCLUSIONS

Nortriptyline, paroxetine, and sertraline may be preferred choices in breast-feeding women. Minimizing the maternal dose may be helpful with citalopram. Current data do not support monitoring breast milk levels in individual patients. Future researchers should report maternal, breast milk, and infant antidepressant levels along with other appropriate variables.

Exposure to postnatal depression predicts elevated cortisol in adolescent offspring

BACKGROUND

Animal research shows that early adverse experience results in altered glucocorticoid levels in adulthood, either raised basal levels or accentuated responses to stress. If a similar phenomenon operates in humans, this suggests a biological mechanism whereby early adversity might transmit risk for major depression, glucocorticoid elevations being associated with the development of this disorder.

METHODS

We measured salivary cortisol at 8:00 am and 8:00 pm over 10 days in 13-year-old adolescents who had (n = 48) or had not (n = 39) been exposed to postnatal maternal depression.

RESULTS

Maternal postnatal depression was associated with higher, more variable morning cortisol in offspring, a pattern previously found to predict major depression.

CONCLUSIONS

Early adverse experiences might alter later steroid levels in humans. Because maternal depression confers added risk for depression to children, these alterations might provide a link between early events and later psychopathology.

Is there an association between life events, postnatal depression and thyroid dysfunction in thyroid antibody positive women?

BACKGROUND

Postnatal depression is more common in women positive for thyroid autoantibodies, independent of thyroid hormone dysfunction, but the basis of this association is unclear.

AIMS

The objective of the work reported here has been to investigate from data obtained from previously published research, a possible association between life events, postnatal depression and the development of thyroid dysfunction in women who are positive for thyroid autoantibodies.

METHOD

A cohort of pregnant women whose thyroid antibody status was positive (N = 115), was identified at antenatal booking (approximately 16 weeks). These, and a group of women negative for thyroid antibodies (N = 123), were assessed for depression at six to eight weeks postpartum and then at 12, 20 and 28 weeks postpartum according to Research Diagnostic Criteria (RDC). The number and type of life events over the preceding year were also assessed at eight weeks postpartum using Paykel's Life Event Schedule. At four weekly intervals post-partum until six months, thyroid antibody levels and thyroid function (plasma T3 T4 and TSH) were measured.

RESULTS

As anticipated, the thyroid antibody status remained the same throughout the study, and there was no difference in the number or type of life events reported in the preceding year, between antibody positive and antibody negative women. Postnatal depression was associated with an excess of both total and negative life events, independent of thyroid antibody status or actual thyroid hormonal status. Women who developed thyroid dysfunction did not report an excess of life events (total, negative or neutral) in the preceding year.

CONCLUSION

There was an excess of reported total and negative life events in women with postnatal depression, but this was independent of thyroid antibody status or function.

The clinical nature and formal diagnosis of premenstrual, postpartum, and perimenopausal affective disorders

Various mood and anxiety disorders are more prevalent in reproductive-aged women, and appear to be linked to hormonal and reproductive events. Premenstrual affective disorders consist of premenstrual syndrome, premenstrual dysphoric disorder, and premenstrual exacerbation of mood or anxiety disorders. Postpartum affective disorders can range from postpartum "blues" to postpartum depression with or without psychosis, and also include anxiety disorders, such as panic disorder, generalized anxiety disorder, social phobia, and obsessive-compulsive disorder. In perimenopausal women, the vulnerability to mood and anxiety disorders is increased. All of these disorders share risk factors, and have etiologic features in common, such as exposure to the rise and fall of ovarian sex steroids. The following is a review of these syndromes and their etiology, diagnosis, and treatment.

Etiology and treatment of postpartum depression

This article reviews the risk factors, pathogenesis, treatment, and prevention of postpartum depression. Postpartum depression is common and occurs in up to 18% of newly delivered mothers. Though the hormonal changes occurring after childbirth are believed to play a role in postpartum depression, no hormonal etiology has been identified. Estrogen appears somewhat helpful for postpartum depression, but its use is limited by problematic medical sequelae. Several antidepressants are effective for postpartum depression and appear safe for use by breastfeeding women. Psychosocial interventions and cultural rituals, which may prevent or ameliorate postpartum depression, have also been employed.