Brexanolone (SAGE-547 injection) in post-partum depression: a randomised controlled trial

Decreased extrasynaptic δ-GABAA receptors in PNN-associated parvalbumin interneurons correlates with anxiety in APP and tau mouse models of Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD) is associated with gradual memory loss and anxiety which affects ~75% of AD patients. This study investigated whether AD-associated anxiety correlated with modulation of extrasynaptic δ-subunit-containing GABAA receptors (δ-GABAARs) in experimental mouse models of AD.

EXPERIMENTAL APPROACH

We combined behavioural experimental paradigms to measure cognition performance, and anxiety with neuroanatomy and molecular biology, using familial knock-in (KI) mouse models of AD that harbour β-amyloid (Aβ) precursor protein App (AppNL-F) with or without humanized microtubule-associated protein tau (MAPT), age-matched to wild-type control mice at three different age windows.

RESULTS

AppNL-F KI and AppNL-F/MAPT AD models showed a similar magnitude of cognitive decline and elevated magnitude of anxiety correlated with neuroinflammatory hallmarks, including triggering receptor expressed on myeloid cells 2 (TREM2), reactive astrocytes and activated microglia consistent with accumulation of Aβ, tau and down-regulation of Wnt/β-catenin signalling compared to aged-matched WT controls. In both the CA1 region of the hippocampus and dentate gyrus, there was an age-dependent decline in the expression of δ-GABAARs selectively expressed in parvalbumin (PV)-expressing interneurons, encapsulated by perineuronal nets (PNNs) in the AD mouse models compared to WT mice. In vivo positive allosteric modulation of the δ-GABAARs, using a δ-selective-compound DS2, decreased the level of anxiety in the AD mouse models, which was correlated with reduced hallmarks of neuroinflammation, and 'normalisation' of the expression of δ-GABAARs.

CONCLUSIONS

Our data show that the δ-GABAARs could potentially be targeted for alleviating symptoms of anxiety, which would greatly improve the quality of life of AD individuals.

Repurposing General Anesthetic Drugs to Treat Depression: A New Frontier for Anesthesiologists in Neuropsychiatric Care

During the last 100 years, the role of anesthesiologists in psychiatry has focused primarily on facilitating electroconvulsive therapy and mitigating postoperative delirium and other perioperative neurocognitive disorders. The discovery of the rapid and sustained antidepressant properties of ketamine, and early results suggesting that other general anesthetic drugs (including nitrous oxide, propofol, and isoflurane) have antidepressant properties, has positioned anesthesiologists at a new frontier in the treatment of neuropsychiatric disorders. Moreover, shared interest in understanding the biologic underpinnings of anesthetic drugs as psychotropic agents is eroding traditional academic boundaries between anesthesiology and psychiatry. This article presents a brief overview of anesthetic drugs as novel antidepressants and identifies promising future candidates for the treatment of depression. The authors issue a call to action and outline strategies to foster collaborations between anesthesiologists and psychiatrists as they work toward the common goals of repurposing anesthetic drugs as antidepressants and addressing mood disorders in surgical patients.

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.

The efficacy of zuranolone versus placebo in postpartum depression and major depressive disorder: a systematic review and meta-analysis

BACKGROUND

Zuranolone, an oral version of allopregnanolone and neurosteroid, is a novel drug for the treatment of major depressive disorder (MDD) and postpartum depression (PPD).

AIM

The purpose of this systematic review and meta-analysis was to assess the efficacy of zuranolone in the treatment of MDD and PPD.

METHOD

A systematic search was conducted using EBSCOhost to simultaneously search Academic Search Premier, APA PsycArticles, APA PsycInfo, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, CINAHL Ultimate, and MEDLINE with Full Text. Two independent reviewers screened the articles and completed a full-text review using Covidence. The quality of each study was assessed using the Cochrane Risk of Bias tool for randomized trials (RoB 2). A meta-analysis was then conducted using Review Manager (RevMan v5.4) software.

RESULTS

The initial search yielded 127 results, with 6 articles fitting our inclusion and exclusion criteria. All 6 studies, comprising 1707 participants, had an overall low risk of bias. There was a significant decrease in HAM-D scores for MDD at 15 days versus placebo (MD - 2.40, 95% CI - 3.07 to - 1.63; p < .001). When pooling data for PDD, there was an overall significant decrease in HAM-D scores at 15 days versus placebo (MD - 4.06, 95% CI - 4.25 to - 3.87; p < .001).

CONCLUSION

The results suggest that zuranolone can improve symptoms of PPD at 15 days; however, results were not clinically significant for MDD. Future research is needed to evaluate the long-term efficacy of zuranolone in PPD and the treatment efficacy in MDD.

Postpartum Depression: A Clinical Review of Impact and Current Treatment Solutions

Depression during the first year postpartum (postpartum depression) impacts millions of women and their families worldwide. In this narrative review, we provide a summary of postpartum depression, examining the etiology and consequences, pharmacological and psychological treatments, and potential mechanisms of change and current barriers to care. Psychological treatments are effective and preferred by many perinatal patients over medications, but they often remain inaccessible. Key potential mechanisms underlying their effectiveness include treatment variables (e.g., dosage and therapeutic alliance) and patient behaviors (e.g., activation and avoidance and emotional regulation). Among pharmacological treatments, the selective serotonin reuptake inhibitor (SSRI) sertraline is generally the first-line antidepressant medication recommended to women in the postpartum period due to its minimal passage into breastmilk and the corresponding decades of safety data. Importantly, most antidepressant drugs are considered compatible with breastfeeding. Neurosteroids are emerging as an effective treatment for postpartum depression, although currently this treatment is not widely available. Barriers to widespread access to treatment include those that are systematic (e.g., lack of specialist providers), provider-driven (e.g., lack of flexibility in treatment delivery), and patient-driven (e.g., stigma and lack of time for treatment engagement). We propose virtual care, task-sharing to non-specialist treatment providers, and collaborative care models as potential solutions to enhance the reach and scalability of effective treatments to address the growing burden of postpartum depression worldwide and its negative impact on families and society.

Prolonged HPA axis dysregulation in postpartum depression associated with adverse early life experiences: A cross-species translational study

Childhood and adolescent stress increase the risk of postpartum depression (PPD), often providing an increased probability of treatment refractoriness. Nevertheless, the mechanisms linking childhood/adolescent stress to PPD remain unclear. Our study investigated the longitudinal effects of adolescent stress on the hypothalamic-pituitary-adrenal (HPA) axis and postpartum behaviors in mice and humans. Adolescent social isolation prolonged glucocorticoid elevation, leading to long-lasting postpartum behavioral changes in female mice. These changes were unresponsive to current PPD treatments but improved with post-delivery glucocorticoid receptor antagonist treatment. Childhood/adolescent stress significantly impacted HPA axis dysregulation and PPD in human females. Repurposing glucocorticoid receptor antagonists for some cases of treatment-resistant PPD may be considered.

Brexanolone Treatment in a Real-World Patient Population: A Case Series and Pilot Feasibility Study of Precision Neuroimaging

PURPOSE/BACKGROUND

Brexanolone is approved for postpartum depression (PPD) by the United States Food and Drug Administration. Brexanolone has outperformed placebo in clinical trials, but less is known about the efficacy in real-world patients with complex social and medical histories. Furthermore, the impact of brexanolone on large-scale brain systems such as changes in functional connectivity (FC) is unknown.

METHODS/PROCEDURES

We tracked changes in depressive symptoms across a diverse group of patients who received brexanolone at a large medical center. Edinburgh Postnatal Depression Scale (EPDS) scores were collected through chart review for 17 patients immediately prior to infusion through approximately 1 year postinfusion. In 2 participants, we performed precision functional neuroimaging (pfMRI), including before and after treatment in 1 patient. pfMRI collects many hours of data in individuals for precision medicine applications and was performed to assess the feasibility of investigating changes in FC with brexanolone.

FINDINGS/RESULTS

The mean EPDS score immediately postinfusion was significantly lower than the mean preinfusion score (mean change [95% CI]: 10.76 [7.11-14.40], t (15) = 6.29, P < 0.0001). The mean EPDS score stayed significantly lower at 1 week (mean difference [95% CI]: 9.50 [5.23-13.76], t (11) = 4.90, P = 0.0005) and 3 months (mean difference [95% CI]: 9.99 [4.71-15.27], t (6) = 4.63, P = 0.0036) postinfusion. Widespread changes in FC followed infusion, which correlated with EPDS scores.

IMPLICATIONS/CONCLUSIONS

Brexanolone is a successful treatment for PPD in the clinical setting. In conjunction with routine clinical care, brexanolone was linked to a reduction in symptoms lasting at least 3 months. pfMRI is feasible in postpartum patients receiving brexanolone and has the potential to elucidate individual-specific mechanisms of action.

Neuroactive Steroids, Toll-like Receptors, and Neuroimmune Regulation: Insights into Their Impact on Neuropsychiatric Disorders

Pregnane neuroactive steroids, notably allopregnanolone and pregnenolone, exhibit efficacy in mitigating inflammatory signals triggered by toll-like receptor (TLR) activation, thus attenuating the production of inflammatory factors. Clinical studies highlight their therapeutic potential, particularly in conditions like postpartum depression (PPD), where the FDA-approved compound brexanolone, an intravenous formulation of allopregnanolone, effectively suppresses TLR-mediated inflammatory pathways, predicting symptom improvement. Additionally, pregnane neurosteroids exhibit trophic and anti-inflammatory properties, stimulating the production of vital trophic proteins and anti-inflammatory factors. Androstane neuroactive steroids, including estrogens and androgens, along with dehydroepiandrosterone (DHEA), display diverse effects on TLR expression and activation. Notably, androstenediol (ADIOL), an androstane neurosteroid, emerges as a potent anti-inflammatory agent, promising for therapeutic interventions. The dysregulation of immune responses via TLR signaling alongside reduced levels of endogenous neurosteroids significantly contributes to symptom severity across various neuropsychiatric disorders. Neuroactive steroids, such as allopregnanolone, demonstrate efficacy in alleviating symptoms of various neuropsychiatric disorders and modulating neuroimmune responses, offering potential intervention avenues. This review emphasizes the significant therapeutic potential of neuroactive steroids in modulating TLR signaling pathways, particularly in addressing inflammatory processes associated with neuropsychiatric disorders. It advances our understanding of the complex interplay between neuroactive steroids and immune responses, paving the way for personalized treatment strategies tailored to individual needs and providing insights for future research aimed at unraveling the intricacies of neuropsychiatric disorders.

Statistical analyses of ordinal outcomes in randomised controlled trials: a scoping review

BACKGROUND

Randomised controlled trials (RCTs) aim to estimate the causal effect of one or more interventions relative to a control. One type of outcome that can be of interest in an RCT is an ordinal outcome, which is useful to answer clinical questions regarding complex and evolving patient states. The target parameter of interest for an ordinal outcome depends on the research question and the assumptions the analyst is willing to make. This review aimed to provide an overview of how ordinal outcomes have been used and analysed in RCTs.

METHODS

The review included RCTs with an ordinal primary or secondary outcome published between 2017 and 2022 in four highly ranked medical journals (the British Medical Journal, New England Journal of Medicine, The Lancet, and the Journal of the American Medical Association) identified through PubMed. Details regarding the study setting, design, the target parameter, and statistical methods used to analyse the ordinal outcome were extracted.

RESULTS

The search identified 309 studies, of which 144 were eligible for inclusion. The most used target parameter was an odds ratio, reported in 78 (54%) studies. The ordinal outcome was dichotomised for analysis in 47 ( 33 % ) studies, and the most common statistical model used to analyse the ordinal outcome on the full ordinal scale was the proportional odds model (64 [ 44 % ] studies). Notably, 86 (60%) studies did not explicitly check or describe the robustness of the assumptions for the statistical method(s) used.

CONCLUSIONS

The results of this review indicate that in RCTs that use an ordinal outcome, there is variation in the target parameter and the analytical approaches used, with many dichotomising the ordinal outcome. Few studies provided assurance regarding the appropriateness of the assumptions and methods used to analyse the ordinal outcome. More guidance is needed to improve the transparent reporting of the analysis of ordinal outcomes in future trials.

Neurosteroids and their potential as a safer class of general anesthetics

Neurosteroids (NS) are a class of steroids that are synthesized within the central nervous system (CNS). Various NS can either enhance or inhibit CNS excitability and they play important biological roles in brain development, brain function and as mediators of mood. One class of NS, 3α-hydroxy-pregnane steroids such as allopregnanolone (AlloP) or pregnanolone (Preg), inhibits neuronal excitability; these endogenous NS and their analogues have been therapeutically applied as anti-depressants, anti-epileptics and general anesthetics. While NS have many favorable properties as anesthetics (e.g. rapid onset, rapid recovery, minimal cardiorespiratory depression, neuroprotection), they are not currently in clinical use, largely due to problems with formulation. Recent advances in understanding NS mechanisms of action and improved formulations have rekindled interest in development of NS as sedatives and anesthetics. In this review, the synthesis of NS, and their mechanism of action will be reviewed with specific emphasis on their binding sites and actions on γ-aminobutyric acid type A (GABAA) receptors. The potential advantages of NS analogues as sedative and anesthetic agents will be discussed.

The role of neurosteroids in posttraumatic stress disorder and alcohol use disorder: A review of 10 years of clinical literature and treatment implications

Rates of alcohol use disorder (AUD) are increasing in men and women and there are high rates of concurrent posttraumatic stress disorder (PTSD) and AUD. AUD and PTSD synergistically increase symptomatology and negatively affect treatment outcomes; however, there are very limited pharmacological treatments for PTSD/AUD. Neurosteroids have been implicated in the underlying neurobiological mechanisms of both PTSD and AUD and may be a target for treatment development. This review details the past ten years of research on pregnenolone, progesterone, allopregnanolone, pregnanolone, estradiol, testosterone and dehydroepiandrosterone/dehydroepiandrosterone-sulfate (DHEA/DHEA-S) in the context of PTSD and AUD, including examination of trauma/alcohol-related variables, such as stress-reactivity. Emerging evidence that exogenous pregnenolone, progesterone, and allopregnanolone may be promising, novel interventions is also discussed. Specific emphasis is placed on examining the application of sex as a biological variable in this body of literature, given that women are more susceptible to both PTSD diagnoses and stress-related alcohol consumption.

Emerging evidence for endogenous neurosteroid modulation of pro-inflammatory and anti-inflammatory pathways that impact neuropsychiatric disease

This mini-review presents emerging evidence that endogenous neurosteroids modulate both pro- and anti-inflammatory signaling by immune cells and brain cells that contribute to depression, alcohol use disorders, and other inflammatory conditions. We first review the literature on pregnenolone and allopregnanolone inhibition of proinflammatory neuroimmune pathways in the periphery and the brain - effects that are independent of GABAergic mechanisms. We follow with evidence for neurosteroid enhancement of anti-inflammatory and protective pathways in brain and immune cells. These studies draw clinical relevance from a large body of evidence that pro-inflammatory immune signaling is dysregulated in many brain disorders and the fact that neurosteroids inhibit the same inflammatory pathways that are activated in depression, alcohol use disorders and other inflammatory conditions. Thus, we describe evidence that neurosteroid levels are decreased and neurosteroid supplementation has therapeutic efficacy in these neuropsychiatric conditions. We conclude with a perspective that endogenous regulation of immune balance between pro- and anti-inflammatory pathways by neurosteroid signaling is essential to prevent the onset of disease. Deficits in neurosteroids may unleash excessive pro-inflammatory activation which progresses in a feed-forward manner to disrupt brain networks that regulate stress, emotion and motivation. Neurosteroids can block various inflammatory pathways in mouse and human macrophages, rat brain and human blood and therefore provide new hope for treatment of intractable conditions that involve excessive inflammatory signaling.

A Comprehensive Review of Novel FDA-Approved Psychiatric Medications (2018-2022)

Mental health disorders are among the top leading causes of disease burden worldwide and many patients have high levels of treatment resistance. Even though medications offer improvement to some patients, antidepressants are only effective in about half of those treated, and schizophrenia is treatment-refractory in about one-third of patients. One way to combat this disparity is to improve medication development and discovery for psychiatric disorders through evidence-based research. Recently, most psychiatric medications approved by the United States Food and Drug Administration (FDA) are for increased tolerability or extended release. Because of the slow, incremental progress, there is a pressing need to explore novel medications with new indications or mechanisms of action to treat the expanding population with mental disorders, especially in those who are fully or partially recalcitrant to first-line medication options. This review aims to present the newest FDA medications with new indications, establish the clinical need for each, and discuss future directions in drug development. We searched and reviewed novel psychiatric medications approved by the FDA from 2018 to 2022. We then analyzed each medication in the United States Clinical Trials Registry and gathered updated results for efficacy and safety information. We also searched PubMed/MEDLINE (Medical Literature Analysis and Retrieval System Online), Scopus, Web of Science, Elsevier, and Google Scholar to understand how these new indications met current clinical needs. Finally, we inquired about related technological implications that will lead the field of psychopharmacology now and in the years to come. We found 12 novel psychiatric medications approved by the FDA from 2018 to 2022, representing a very small percentage of the total FDA approvals during that period. These psychiatric medications with novel mechanisms or improved efficacy and safety  are expected to provide further options for treating mental health disorders; promising results will lead to new patterns of research.

Female sex steroids and epilepsy: Part 2. A practical and human focus on catamenial epilepsy

Catamenial epilepsy is the best described and most researched sex steroid-specific seizure exacerbation. Yet despite this there are no current evidence-based treatments, nor an accepted diagnostic tool. The best tool we currently have is tracking seizures over menstrual cycles; however, the reality of tracking seizures and menstrual cycles is fraught with challenges. In Part 1 of this two-part review, we outlined the often complex and reciprocal relationship between seizures and sex steroids. An adaptable means of tracking is required. In this review, we outline the extent and limitations of current knowledge on catamenial epilepsy. We use sample data to show how seizure exacerbations can be tracked in short/long and even irregular menstrual cycles. We describe how seizure severity, an often overlooked and underresearched form of catamenial seizure exacerbation, can also be tracked. Finally, given the lack of treatment options for females profoundly affected by catamenial epilepsy, Section 3 focuses on current methods and models for researching sex steroids and seizures as well as limitations and future directions. To permit more informative, mechanism-focused research in humans, the need for both a consistent classification of catamenial epilepsy and an objective biomarker is highlighted.

Postmarketing safety profile of brexanolone: a pharmacovigilance analysis based on FDA Adverse Event Reporting System (FAERS)

OBJECTIVE

Brexanolone (Zulresso®) that was approved for the USA in March 2019 is indicated for the treatment of postpartum depression (PPD), but information on adverse drug reactions (ADRs) associated with its use is limited. The main aim of this study was to explore the postmarketing safety profile of brexanolone.

METHODS

In our case/non-case pharmacovigilance study based on the FDA Adverse Event Reporting System (FAERS), the reporting odds ratio and information component with 95% confidence intervals were estimated as measures of disproportionate reporting. Primary disproportionality analyses were performed by comparing brexanolone with all other drugs or selective serotonin reuptake inhibitors (SSRIs). Sensitivity analyses were performed on a subset of perinatal depression.

RESULTS

We identified 267 cases using brexanolone. Brexanolone was reported as a primary or secondary suspect drug in most cases (n = 260, 97.38%). Of the total brexanolone cases, positive dechallenge and discontinuation accounted for 12.36% (n = 33) and 26.22% (n = 70), respectively. Serious outcomes were reported in 11.61% (n = 31) patients. Compared to all the other drugs or SSRIs within the same time window, the reporting risks of brexanolone were mainly from psychiatric and nervous systems. Sensitivity analyses indicated that these significant disproportionalities were mostly retained.

CONCLUSION

Our pharmacovigilance analysis showed a high reporting frequency of psychiatric and nervous system ADRs associated with the use of brexanolone. In additional prospective research, these signals urgently need to be clarified.

Efficacy and tolerability of zuranolone in patients with depression: a meta-analysis of randomized controlled trials

Background: As a novel antidepressant drug, zuranolone has been initially applied in treating depression. This study investigated the efficacy and safety of its administration in patients with depression. Methods: The Embase, PubMed, and Cochrane library databases were searched for available studies up to 1 Nov 2023. The primary outcome was the change on day 15 depression severity scores compared to baseline. Secondary outcomes included remission and response rates on day 15. Safety outcomes included incidence of treatment-emergent adverse events (TEAEs) and individual AEs. Trial sequential analysis (TSA) was used to evaluate the ideal samplesize. Results: Six studies with 1884 patients were included. Zuranolone offered significantly greater changes in day 15 depression severity scores (mean difference = 2.43, 95% confidence interval [CI]: 1.36 to 3.49, p < 0.00001) compared to placebo; this was also observed at other time points. Differences in response (relative risk [RR] = 1.33, 95% CI: 1.15 to 1.54, p < 0.0001) and remission (RR = 1.46, 95% CI: 1.15 to 1.85, p = 0.002) rates were also statistically significant. For safety outcomes, zuranolone group showed more incidence of TEAE than the placebo group (RR: 1.15, 95% CI: 1.06 to 1.25, p = 0.0005, I 2 = 0%). As for individual AEs, significant differences were observed in dizziness (RR = 2.17, 95% CI: 1.22 to 3.86, p = 0.008) and somnolence (RR = 2.43, 95% CI: 1.35 to 4.37, p = 0.003. No significant difference was observed in other AEs. The result of TSA indicated that the cumulative curve crossed the conventional (Z = 1.96) boundary but not reach TSA boundary (RIS = 1910). Conclusion: Our findings suggest that zuranolone has a rapid short-term antidepressant effect during administration. Although more TEAEs were observed in zuranolone, most of them were slight and temporary. However, studies with larger sample sizes and longer follow-up are needed. Systematic Review Registration: https://inplasy.com/inplasy-2023-5-0104/, identifier INPLASY202350104.

Distinguishing features of depression in dementia from primary psychiatric disease

Depression is a common and devastating neuropsychiatric symptom in the elderly and in patients with dementia. In particular, nearly 80% of patients with Alzheimer's Disease dementia experience depression during disease development and progression. However, it is unknown whether the depression in patients with dementia shares the same molecular mechanisms as depression presenting as primary psychiatric disease or occurs and persists through alternative mechanisms. In this review, we discuss how the clinical presentation and treatment differ between depression in dementia and as a primary psychiatric disease, with a focus on major depressive disorder. Then, we hypothesize several molecular mechanisms that may be unique to depression in dementia such as neuropathological changes, inflammation, and vascular events. Finally, we discuss existing issues and future directions for investigation and treatment of depression in dementia.

Effect of Dexmedetomidine on Postpartum Depression in Women With Prenatal Depression: A Randomized Clinical Trial

Importance

Postpartum depression (PPD) is emerging as a major public health problem worldwide. Although the particular period and context in which PPD occurs provides an opportunity for preventive interventions, there is still a lack of pharmacologic prevention strategies for PPD.

Objective

To assess the efficacy and safety of dexmedetomidine for prevention of PPD among women with prenatal depression undergoing cesarean delivery.

Design, Setting, and Participants

This randomized clinical trial enrolled 338 women who screened positive for prenatal depression at 2 hospitals in Hunan, China from March 28, 2022, to April 16, 2023. Women with an Edinburgh Postnatal Depression Scale score of more than 9 who were 18 years of age or older and were scheduled for elective cesarean delivery were eligible.

Interventions

Eligible participants were randomly assigned in a 1:1 ratio to either the dexmedetomidine group or the control group via centrally computer-generated group randomization. Dexmedetomidine, 0.5 μg/kg and 0.9% saline were intravenously infused for 10 minutes after delivery in the dexmedetomidine and control groups, respectively. After infusion, sufentanil or dexmedetomidine plus sufentanil was administered via patient-controlled intravenous analgesia for 48 hours in the control group and dexmedetomidine group, respectively.

Main Outcomes and Measures

The primary outcome was positive PPD screening results at 7 and 42 days post partum, defined as a postpartum Edinburgh Postnatal Depression Scale score of more than 9. Analysis was on an intention-to-treat basis.

Results

All 338 participants were female, with a mean (SD) age of 31.5 (4.1) years. Positive PPD screening incidence at 7 and 42 days post partum in the dexmedetomidine group vs the control group was significantly decreased (day 7, 21 of 167 [12.6%] vs 53 of 165 [32.1%]; risk ratio, 0.39 [95% CI, 0.25-0.62]; P < .001; day 42, 19 of 167 [11.4%] vs 50 of 165 [30.3%]; risk ratio, 0.38 [95% CI, 0.23-0.61]; P < .001). The dexmedetomidine group showed no significant difference in adverse events vs the control group (46 of 169 [27.2%] vs 33 of 169 [19.5%]; P = .10), but the incidence of hypotension increased (31 of 169 [18.3%] vs 16 of 169 [9.5%]; risk ratio, 2.15 [95% CI, 1.13-4.10]; P = .02).

Conclusions and Relevance

Dexmedetomidine administration in the early postpartum period significantly reduced the incidence of a positive PPD screening and maintained a favorable safety profile.

Trial Registration

Chinese Clinical Trial Registry Identifier: ChiCTR2200057213.

Finding new and better treatments for psychiatric disorders

In contrast to most fields of medicine, progress to discover and develop new and improved psychiatric drugs has been slow and disappointing. The vast majority of currently prescribed drugs to treat schizophrenia, mood and anxiety disorders are arguably no more effective than the first generation of psychiatric drugs introduced well over 50 years ago. With only a few exceptions current psychiatric drugs work via the same fundamental mechanisms of action as first-generation agents. Here we describe the reasons for this slow progress and outline a number of areas of research that involve a greater reliance on experimental therapeutics utilizing recent advances in neuroscience to better understand disease biology. We exemplify the potential impact of these areas of research focus with several recent examples of novel agents that have emerged and which support our optimism that newer, more effective and better tolerated agents, are on the horizon. Together with existing drugs these newer agents and novel mechanisms could offer markedly improved functional outcomes for the millions of people still disabled by psychiatric disorders.

No time to lose: the current state of research in rapid-acting psychotherapeutics

The vast majority of treatments for psychiatric and substance use disorders take weeks to work. Notable exceptions to this rule exist, with some treatments such as intravenous ketamine resolving symptoms in minutes to hours. Current research is focused on identifying novel approaches to rapid-acting psychotherapeutics. Promising results from studies of novel classes of drugs and innovative brain stimulation therapies are currently being studied through both clinical and pre-clinical research, as described here. Research focused on understanding neurobiological mechanisms, effective therapeutic context, and implementation approaches are needed to maximize the potential reach of these therapies.

The Role of Extrasynaptic GABA Receptors in Postpartum Depression

Postpartum depression is a serious disease with a high incidence and severe impact on pregnant women and infants, but its mechanism remains unclear. Recent studies have shown that GABA receptors, especially extrasynaptic receptors, are closely associated with postpartum depression. There are many different structures of GABA receptors, so different types of receptors have different functions, even though they transmit information primarily through GABA. In this review, we focus on the function of GABA receptors, especially extrasynaptic GABA receptors, and their association with postpartum depression. We have shown that the extrasynaptic GABA receptor has a significant impact on the activity and function of neurons through tonic inhibition. The extrasynaptic receptor and its ligands undergo drastic changes during pregnancy and childbirth. Abnormal changes or the body's inability to adjust and recover may be an important cause of postpartum depression. Finally, by reviewing the mechanisms of several novel antidepressants, we suggest that extrasynaptic receptors may be potential targets for the treatment of postpartum depression.

Efficacy and safety of zuranolone for the treatment of depression: A systematic review and meta-analysis

Major depressive disorder (MDD) and postpartum depression (PPD) are common and burdensome conditions. This study aims to evaluate the efficacy and safety of zuranolone, a neuroactive steroid γ-aminobutyric acid type A receptors-positive allosteric modulator, in treating MDD and PPD. A comprehensive literature search was conducted until September 2023, identifying seven randomized controlled trials (RCTs). The results demonstrated that zuranolone significantly decreased Hamilton Rating Scale for Depression (HAM-D) scores in patients with PPD or MDD at day 15 (concluding the 14-day course) and day 42-45 (4 weeks after treatment cessation) compared with the placebo, albeit exhibiting a diminishing trend. Moreover, a higher percentage of patients with PPD or MDD achieved HAM-D response and remission with zuranolone treatment compared with placebo at day 15. However, zuranolone did not significantly increase the proportion of MDD patients achieving HAM-D remission at 42/43 days. Adverse events (AEs) such as somnolence, dizziness, and sedation were linked to zuranolone, with a higher but not statistically significant rate of discontinuation due to AEs in the zuranolone group. Overall, our findings support the rapid antidepressant effects of zuranolone in MDD and PPD, along with a relatively favorable safety and tolerability. Large-scale longitudinal RCTs are needed to evaluate the long-term efficacy of zuranolone.

Neurosteroids: mechanistic considerations and clinical prospects

Like other classes of treatments described in this issue's section, neuroactive steroids have been studied for decades but have risen as a new class of rapid-acting, durable antidepressants with a distinct mechanism of action from previous antidepressant treatments and from other compounds covered in this issue. Neuroactive steroids are natural derivatives of progesterone but are proving effective as exogenous treatments. The best understood mechanism is that of positive allosteric modulation of GABAA receptors, where subunit selectivity may promote their profile of action. Mechanistically, there is some reason to think that neuroactive steroids may separate themselves from liabilities of other GABA modulators, although research is ongoing. It is also possible that intracellular targets, including inflammatory pathways, may be relevant to beneficial actions. Strengths and opportunities for further development include exploiting non-GABAergic targets, structural analogs, enzymatic production of natural steroids, precursor loading, and novel formulations. The molecular mechanisms of behavioral effects are not fully understood, but study of brain network states involved in emotional processing demonstrate a robust influence on affective states not evident with at least some other GABAergic drugs including benzodiazepines. Ongoing studies with neuroactive steroids will further elucidate the brain and behavioral effects of these compounds as well as likely underpinnings of disease.

The cost-effectiveness of zuranolone versus selective serotonin reuptake inhibitors for the treatment of postpartum depression in the United States

AIMS

The objective of this research is to evaluate the cost-effectiveness of zuranolone, the first oral treatment indicated for postpartum depression (PPD) in adults approved by the United States Food and Drug Administration.

METHODS

Zuranolone and selective serotonin reuptake inhibitor (SSRI) trial-based efficacy was derived from an indirect treatment comparison. Long-term efficacy outcomes were based on a large longitudinal cohort study. Maternal health utility values were derived from trial-based, short-form 6-D responses. Other inputs were derived from literature and economic data from the US Bureau of Labor Statistics. We estimated costs (2023 US dollars) and quality-adjusted life-years (QALYs) for patients with PPD treated with zuranolone (14-day dosing) or SSRIs (chronic dosing). The indirect costs and QALYs of the children and partners were also estimated.

RESULTS

The incremental cost-effectiveness ratio for zuranolone versus SSRIs was $94,741 per QALY gained over an 11-year time horizon. Maternal total direct medical costs averaged $84,318 in the zuranolone arm, compared to $86,365 in the SSRI arm. Zuranolone-treated adults averaged 6.178 QALYs compared to 6.116 QALYs for the SSRI arm. Costs and utilities for the child and partner were also included in the base case. Drug and administration costs for zuranolone averaged $15,902, compared to $30 for SSRIs over the studied time horizon. Results were sensitive to the model time horizon.

LIMITATIONS

As head-to-head trials were not available to permit direct comparison, efficacy inputs were derived from an indirect treatment comparison which can be confounded by cross-trial differences. The data used are reflective of a general PPD population rather than marginalized individuals who may be at a greater risk for adverse PPD outcomes. The model likely excludes unmeasured effects for patient, child, and partner.

CONCLUSIONS

This economic model's results suggest that zuranolone is a more cost-effective therapy compared to SSRIs for treating adults with PPD.

Indirect comparisons of relative efficacy estimates of zuranolone and selective serotonin reuptake inhibitors for postpartum depression

AIMS

Estimate relative efficacy of zuranolone, a novel oral, Food and Drug Administration-approved treatment for postpartum depression (PPD) in adults vs. selective serotonin reuptake inhibitors (SSRIs) and combination therapies used for PPD in the United States.

MATERIALS AND METHODS

Randomized controlled trials (RCTs) for zuranolone and SSRIs, identified from systematic review, were used to construct evidence networks, linking via common comparator arms. Due to heterogeneity in placebo responses, matching-adjusted indirect comparison (MAIC) was applied, statistically weighting the zuranolone treatment arm of Phase 3 SKYLARK Study (NCT04442503) to the placebo arm of RCTs investigating SSRIs for PPD. MAIC outputs were applied in Bucher indirect treatment comparisons (ITCs) and network meta-analysis (NMA), using Edinburgh Postnatal Depression Scale (EPDS) and 17-item Hamilton Rating Scale for Depression (HAMD-17) change from baseline (CFB) on Days 3, 15, 28 (Month 1), 45, and last observation (Day 45, Week 12/18).

RESULTS

Larger EPDS CFB was observed among zuranolone-treated vs. SSRI-treated patients from Day 15 onward. Zuranolone-treated (vs. SSRI-treated) patients exhibited 4.22-point larger reduction in EPDS by Day 15 (95% confidence interval: -6.16, -2.28) and 7.43-point larger reduction at Day 45 (-9.84, -5.02) with Bucher ITC. NMA showed EPDS reduction for zuranolone was 4.52 (-6.40, -2.65) points larger than SSRIs by Day 15 and 7.16 (-9.47, -4.85) larger at Day 45. Lack of overlap between study populations substantially reduced effective sample size post-matching, making HAMD-17 CFB analysis infeasible.

LIMITATIONS

Limited population overlap between SKYLARK Study and RCTs reduced feasibility of undertaking HAMD-17 CFB ITCs and may introduce uncertainty to EPDS CFB ITC results.

CONCLUSIONS

Analysis showed zuranolone-treated patients with PPD experienced greater symptom improvement than SSRI-treated patients from Day 15 onward, with largest mean difference at Day 45. Adjusting for differences between placebo arms, zuranolone may be associated with greater PPD symptom improvement (measured by EPDS) vs. SSRIs.

Novel neurosteroid therapeutics for post-partum depression: perspectives on clinical trials, program development, active research, and future directions

This article reviews novel neurosteroid therapeutics for post-partum depression, with a focus on their development, clinical trial data, current practices, and future directions in this exciting field. We discuss the clinical impact of brexanolone and several other neurosteroids, particularly as they relate to the treatment of postpartum depression (PPD) and major depressive disorders outside of the perinatal period. There has been increasing interest in GABA signaling and modulation as it pertains to the development of altered circuity and depressive states. This scientific underpinning served as the rationale for the initial development of brexanolone. We review the clinical trials supporting its Food and Drug Administration (FDA) approval as the first rapidly acting antidepressant specific for PPD, and the subsequent development of a clinical brexanolone program at an academic medical center, highlighting new research and data from that site as well as the challenges with the delivery of this I.V. drug. In addition to the GABA signaling hypothesis, we discuss the new evidence demonstrating that brexanolone inhibits inflammatory signaling post-infusion, suggesting that inflammatory signaling may contribute to the etiology of PPD. Finally, we describe new and future directions in neurosteroid therapeutics, including the development of an oral agent, zuranolone, and the IV and oral formulations of ganaxolone. Ultimately, the hope is that these novel neurosteroid therapeutics will provide fast-acting treatment for these impairing disorders and improve our understanding of the underlying mechanisms of depressive disorders.

Mitochondrial might: powering the peripartum for risk and resilience

The peripartum period, characterized by dynamic hormonal shifts and physiological adaptations, has been recognized as a potentially vulnerable period for the development of mood disorders such as postpartum depression (PPD). Stress is a well-established risk factor for developing PPD and is known to modulate mitochondrial function. While primarily known for their role in energy production, mitochondria also influence processes such as stress regulation, steroid hormone synthesis, glucocorticoid response, GABA metabolism, and immune modulation - all of which are crucial for healthy pregnancy and relevant to PPD pathology. While mitochondrial function has been implicated in other psychiatric illnesses, its role in peripartum stress and mental health remains largely unexplored, especially in relation to the brain. In this review, we first provide an overview of mitochondrial involvement in processes implicated in peripartum mood disorders, underscoring their potential role in mediating pathology. We then discuss clinical and preclinical studies of mitochondria in the context of peripartum stress and mental health, emphasizing the need for better understanding of this relationship. Finally, we propose mitochondria as biological mediators of resilience to peripartum mood disorders.

Zuranolone - synthetic neurosteroid in treatment of mental disorders: narrative review

With each passing year, the number of people suffering from mental disorders grows at a disturbing speed. Neuroactive steroids are a new promising group of drugs with the potential for use in many diseases like postpartum depression, postnatal psychosis, major depression, insomnia, bipolar disorder, and Parkinson's tremor, due to their ability to modulate the activity of GABAA receptor. Neurosteroids are progesterone metabolites that are synthesized from cholesterol or steroid hormones in various brain regions. They regulate neuronal development, regeneration, and neurotransmission. They are implicated in mood disorders, anxiety disorders, schizophrenia, PTSD, and impulsive aggression. Neurosteroids have been studied for their potential to prevent or treat neurodegenerative diseases such as Alzheimer's disease and HIV-associated dementia. They can promote neurogenesis, neuronal survival, myelination, and memory function. They can also affect the growth and sensitivity of hormone-dependent brain tumors such as gliomas. Zuranolone, a newly registered neurosteroid drug has shown huge flexibility in both clinical and ambulatory treatment thanks to its pharmacokinetic traits, especially the possibility for oral administration, unlike its predecessor Brexanolone. Zuranolone is a synthetic positive allosteric modulator of the GABAA receptor that can be taken orally. The review aims to summarize the current knowledge on zuranolone as a novel neurosteroid drug for various mental disorders, especially for postpartum mental disorders for which this drug was meant originally. It covers studies indexed in the PubMed, Scopus, and Web of Science databases published since 2017. Keywords used in the search, as well as inclusion and exclusion criteria, are given in the aims and methodology section. The review explains the evidence for the role of neurosteroids, especially allopregnanolone, in the pathophysiology and treatment of postpartum depression. It discusses the mechanisms of neurosteroid action, the changes in neurosteroid levels during pregnancy and postpartum, and the clinical trials of brexanolone and zuranolone, two synthetic analogs of allopregnanolone, for postpartum depression. It provides an overview of the biosynthesis and metabolism of neurosteroids in the central and peripheral nervous system. Furthermore, it explains the different sources and pathways of neurosteroid production and the factors that influence their synthesis and regulation, such as stress, hormones, drugs, and genetic variations. The review also explores the potential relevance of neurosteroids for other psychiatric disorders, such as major depression, bipolar disorder, post-traumatic stress disorder (PTSD), schizophrenia, and premenstrual dysphoric disorder. Finally, it highlights the associations between neurosteroid levels and symptom severity and the effects of neurosteroid modulation on mood, cognition, and neuroplasticity.

Promising new pharmacological targets for depression: The search for efficacy

Pharmacological treatment of major depressive disorder (MDD) still relies on the use of serotonergic drugs, despite their limited efficacy. A few mechanistically new drugs have been developed in recent years, but many fail in clinical trials. Several hypotheses have been proposed to explain MDD pathophysiology, indicating that physiological processes such as neuroplasticity, circadian rhythms, and metabolism are potential targets. Here, we review the current state of pharmacological treatments for MDD, as well as the preclinical and clinical evidence for an antidepressant effect of molecules that target non-serotonergic systems. We offer some insights into the challenges facing the development of new antidepressant drugs, and the prospect of finding more effectiveness for each target discussed.

Neuroendocrine insights into neurosteroid therapy for postpartum depression

Postpartum depression (PPD) is associated with a decline in progesterone-derived anxiolytic-antidepressant neurosteroids after delivery. Neurosteroid replacement therapy (NRT) with GABA-A receptor-modulating allopregnanolone (brexanolone) shows promise as the first drug treatment for PPD. Here we describe the molecular insights of the neurosteroid approach for rapid relief of PPD symptoms compared with traditional antidepressants.

Current pharmacotherapy approaches and novel GABAergic antidepressant development in postpartum depression

Postpartum depression has deleterious effects on childbearing persons globally. Existing treatments have been largely extrapolated from those for other forms of depression and have included pharmacotherapy, psychotherapy, and neuromodulation. Hormonal treatments with oestrogen and progestogens, thought to be a rational approach to treatment in response to an emerging literature on the pathophysiology of postpartum depression, have only limited evidence for efficacy to date. Novel antidepressant development with allopregnanolone analogues, in contrast, has proven a promising avenue for the development of rationally designed and efficacious treatments. This state-of-the-art review presents the evidence for the current standard-of-care pharmacotherapy, hormonal treatment, and emerging allopregnanolone analogues for the treatment of postpartum depression along with a discussion of the current understanding of its neuroactive steroid-driven pathophysiology.

Meta-Analyses of Genome-Wide Association Studies for Postpartum Depression

OBJECTIVE

Postpartum depression (PPD) is a common subtype of major depressive disorder (MDD) that is more heritable, yet is understudied in psychiatric genetics. The authors conducted meta-analyses of genome-wide association studies (GWASs) to investigate the genetic architecture of PPD.

METHOD

Meta-analyses were conducted on 18 cohorts of European ancestry (17,339 PPD cases and 53,426 controls), one cohort of East Asian ancestry (975 cases and 3,780 controls), and one cohort of African ancestry (456 cases and 1,255 controls), totaling 18,770 PPD cases and 58,461 controls. Post-GWAS analyses included 1) single-nucleotide polymorphism (SNP)-based heritability ([Formula: see text]), 2) genetic correlations between PPD and other phenotypes, and 3) enrichment of the PPD GWAS findings in 27 human tissues and 265 cell types from the mouse central and peripheral nervous system.

RESULTS

No SNP achieved genome-wide significance in the European or the trans-ancestry meta-analyses. The [Formula: see text] of PPD was 0.14 (SE=0.02). Significant genetic correlations were estimated for PPD with MDD, bipolar disorder, anxiety disorders, posttraumatic stress disorder, insomnia, age at menarche, and polycystic ovary syndrome. Cell-type enrichment analyses implicate inhibitory neurons in the thalamus and cholinergic neurons within septal nuclei of the hypothalamus, a pattern that differs from MDD.

CONCLUSIONS

While more samples are needed to reach genome-wide levels of significance, the results presented confirm PPD as a polygenic and heritable phenotype. There is also evidence that despite a high correlation with MDD, PPD may have unique genetic components. Cell enrichment results suggest GABAergic neurons, which converge on a common mechanism with the only medication approved by the U.S. Food and Drug Administration for PPD (brexanolone).

Research Trends and Hot Spots of Allopregnanolone Research in the Last 20 Years: A Bibliometric Analysis

Background

Allopregnanolone is a kind of neuroactive steroid or neurosteroid in the central nervous system that acts as an endogenenous GABAA receptor positive modulator. However, at present, no comprehensive bibliometric analysis regarding allopregnanolone research is available. In our study, we intend to analyze the research trends and hot spots related to allopregnanolone in the past 20 years.

Methods

We searched for allopregnanolone related articles and reviews between 2004 and 2023 from the Web of Science Core Collection database. Then, the bibliometric analysis was conducted using VOSviewer, CiteSpace, Microsoft Excel 2019, as well as the online bibliometric analysis platform (http://bibliometric.com/).

Results

A total of 1841 eligible publications were identified. The number of annual publications and citations was generally on the rise. Among countries, the United States ranked first in overall publications, citations, international cooperation, and the number of research institutions. The University of North Carolina was the most active institution, conducting numerous preclinical and clinical work that focusing on allopregnanolone treatment for diverse psychiatric or neurologic disorders. As for authors, Dr. Frye CA, Morrow AL, and Pinna G were identified as the top three prolific scholars due to their great publications and citations. Based on the publication clusters and citation bursts analysis, the keyword co-occurrence network, the strongest citation bursts, and co-cited references analysis, the hot spots in recent years included "depression", "postpartum depression", "GABAA receptor", and so on.

Conclusion

Allopregnanolone is still a popular area of research, and the United States leads the way in this area. Dr. Frye CA, Morrow AL, Pinna G, and their teams contributed greatly to the mechanism study and translation study of allopregnanolone. The use of allopregnanolone for the treatment of psychiatric or neurologic disorders, especially postpartum depression, is the current hot spot. However, the underlying mechanisms of anti-depression are still not clear, deserving more in-depth research.

Courtes A, Jones G, Soares JC, Machado-Vieira R. Pharmacotherapies Targeting GABA-Glutamate Neurotransmission for Treatment-Resistant Depression

Treatment-resistant depression (TRD) is a term used to describe a particular type of major depressive disorder (MDD). There is no consensus about what defines TRD, with various studies describing between 1 and 4 failures of antidepressant therapies, with or without electroconvulsive therapy (ECT). That is why TRD is such a growing concern among clinicians and researchers, and it explains the necessity for investigating novel therapeutic targets beyond conventional monoamine pathways. An imbalance between two primary central nervous system (CNS) neurotransmitters, L-glutamate and γ-aminobutyric acid (GABA), has emerged as having a key role in the pathophysiology of TRD. In this review, we provide an evaluation and comprehensive review of investigational antidepressants targeting these two systems, accessing their levels of available evidence, mechanisms of action, and safety profiles. N-methyl-D-aspartate (NMDA) receptor antagonism has shown the most promise amongst the glutamatergic targets, with ketamine and esketamine (Spravato) robustly generating responses across trials. Two specific NMDA-glycine site modulators, D-cycloserine (DCS) and apimostinel, have also generated promising initial safety and efficacy profiles, warranting further investigation. Combination dextromethorphan-bupropion (AXS-05/Auvelity) displays a unique mechanism of action and demonstrated positive results in particular applicability in subpopulations with cognitive dysfunction. Currently, the most promising GABA modulators appear to be synthetic neurosteroid analogs with positive GABAA receptor modulation (such as brexanolone). Overall, advances in the last decade provide exciting perspectives for those who do not improve with conventional therapies. Of the compounds reviewed here, three are approved by the Food and Drug Administration (FDA): esketamine (Spravato) for TRD, Auvelity (dextromethorphan-bupropion) for major depressive disorder (MDD), and brexanolone (Zulresso) for post-partum depression (PPD). Notably, some concerns have arisen with esketamine and brexanolone, which will be detailed in this study.

Clinical efficacy and safety of Zuranolone (SAGE-217) in individuals with major depressive disorder

Major depressive disorder (MDD) is a common mental disorder with a high rate of morbidity and mortality. Dysfunctional signaling of gamma-aminobutyric acid (GABA) has been implicated in some studies in the etiology of MDD. Zuranolone (SAGE-217) is a novel, oral neuroactive steroid and an investigational positive allosteric modulator of synaptic and extrasynaptic GABAA receptors. Herein, we aimed to evaluate the efficacy and safety of Zuranolone in individuals with MDD. We reviewed seven studies including 1662 participants with MDD. Zuranolone was investigated as an oral, once-daily, 14-day treatment course. The results of our synthesis indicate that the antidepressant effects of Zuranolone are rapid, clinically meaningful, and replicated across multiple randomized clinical trials. In addition to replicated efficacy, Zuranolone is associated with an acceptable level of treatment-emergent adverse events and discontinuation without serious adverse events. It is believed that Zuranolone's antidepressant effects arise from its ability to enhance inhibitory GABAergic signaling by increasing synaptic and extrasynaptic GABAA activity and regulation of GABAA receptor expression. Taken together, preliminary evidence suggests the potential for antidepressant effects of Zuranolone. Zuranolone has been approved by FDA for postpartum depression, and is showing efficacy in major depressive disorder. Future research vistas should seek to determine the durability of this treatment approach as well as its effects on domain-specific outcomes (e.g., anhedonia, circadian rhythm, arousal systems) along with application in other diagnostic entities (e.g., bipolar depression).

Cryo-EM structures reveal native GABAA receptor assemblies and pharmacology

Type A γ-aminobutyric acid receptors (GABAARs) are the principal inhibitory receptors in the brain and the target of a wide range of clinical agents, including anaesthetics, sedatives, hypnotics and antidepressants1-3. However, our understanding of GABAAR pharmacology has been hindered by the vast number of pentameric assemblies that can be derived from 19 different subunits4 and the lack of structural knowledge of clinically relevant receptors. Here, we isolate native murine GABAAR assemblies containing the widely expressed α1 subunit and elucidate their structures in complex with drugs used to treat insomnia (zolpidem (ZOL) and flurazepam) and postpartum depression (the neurosteroid allopregnanolone (APG)). Using cryo-electron microscopy (cryo-EM) analysis and single-molecule photobleaching experiments, we uncover three major structural populations in the brain: the canonical α1β2γ2 receptor containing two α1 subunits, and two assemblies containing one α1 and either an α2 or α3 subunit, in which the single α1-containing receptors feature a more compact arrangement between the transmembrane and extracellular domains. Interestingly, APG is bound at the transmembrane α/β subunit interface, even when not added to the sample, revealing an important role for endogenous neurosteroids in modulating native GABAARs. Together with structurally engaged lipids, neurosteroids produce global conformational changes throughout the receptor that modify the ion channel pore and the binding sites for GABA and insomnia medications. Our data reveal the major α1-containing GABAAR assemblies, bound with endogenous neurosteroid, thus defining a structural landscape from which subtype-specific drugs can be developed.

Importance of achieving rapid treatment response in major depressive disorder

Major depressive disorder (MDD) is a leading contributor to disability worldwide and is associated with increased morbidity and mortality. Current pharmacologic treatment options may be ineffective for some patients and can pose several limitations and challenges, including suboptimal response and slow onset of action. Many of these therapies can take 6 to 8 weeks for patients to achieve response and 12 weeks or longer to demonstrate full clinical benefit. Delays in depressive symptom resolution are associated with poor symptomatic and functional outcomes, decreased quality of life, and increased burden on the healthcare system. Achieving response and remission of symptoms soon after diagnosis and treatment is associated with lower rates of relapse and a greater likelihood of functional recovery. An unmet need exists for innovative treatments that offer rapid and sustained effects. This editorial discusses the benefits of rapid improvement in depressive symptoms with available and investigational agents for patients with MDD.

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

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

Neurosteroids and translocator protein 18 kDa (TSPO) in depression: implications for synaptic plasticity, cognition, and treatment options

There is need for novel fast acting treatment options in affective disorders. 3α-reduced neurosteroids such as allopregnanolone are powerful positive allosteric modulators of GABAA receptors and target also extrasynaptic receptors. Their synthesis is mediated by the translocator protein 18 kDa (TSPO). TSPO ligands not only promote endogenous neurosteroidogenesis, but also exert a broad spectrum of functions involving modulation of mitochondrial activity and acting as anti-inflammatory and neuroregenerative agents. Besides affective symptoms, in depression cognitive impairment can be frequently observed, which may be ameliorated through targeting of extrasynaptic GABAA receptors either via TSPO ligands or exogenously administered 3α-reduced neurosteroids. Interestingly, recent findings indicate an enhanced activation of the complement system, e.g., enhanced expression of C1q, both in depression and dementia. It is of note that benzodiazepines have been shown to reduce long-term potentiation and to cause cognitive decline. Intriguingly, TSPO may be crucial in mediating the effects of benzodiazepines on synaptic pruning. Here, we discuss how benzodiazepines and TSPO may interfere with synaptic pruning. Moreover, we highlight recent developments of TSPO ligands and 3α-reduced neurosteroids as therapeutic agents. Etifoxine is the only clinically available TSPO ligand so far and has been studied in anxiety disorders. Regarding 3α-reduced neurosteroids, brexanolone, an intravenous formulation of allopregnanolone, has been approved for the treatment of postpartum depression and zuranolone, an orally available 3α-reduced neurosteroid, is currently being studied in major depressive disorder and postpartum depression. As such, 3α-reduced neurosteroids and TSPO ligands may constitute promising treatment approaches for affective disorders.

GABAA receptors as targets for treating affective and cognitive symptoms of depression

In the past 20 years, our understanding of the pathophysiology of depression has evolved from a focus on an imbalance of monoaminergic neurotransmitters to a multifactorial picture including an improved understanding of the role of glutamatergic excitatory and GABAergic inhibitory neurotransmission. FDA-approved treatments targeting the glutamatergic [esketamine for major depressive disorder (MDD)] and GABAergic (brexanolone for peripartum depression) systems have become available. This review focuses on the GABAA receptor (GABAAR) system as a target for novel antidepressants and discusses the mechanisms by which modulation of δ-containing GABAARs with neuroactive steroids (NASs) or of α5-containing GABAARs results in antidepressant or antidepressant-like actions and discusses clinical data on NASs. Moreover, a potential mechanism by which α5-GABAAR-positive allosteric modulators (PAMs) may improve cognitive deficits in depression is presented.

Preclinical and clinical pharmacology of brexanolone (allopregnanolone) for postpartum depression: a landmark journey from concept to clinic in neurosteroid replacement therapy

This article describes the critical role of neurosteroids in postpartum depression (PPD) and outlines the landmark pharmacological journey of brexanolone as a first-in-class neurosteroid antidepressant with significant advantages over traditional antidepressants. PPD is a neuroendocrine disorder that affects about 20% of mothers after childbirth and is characterized by symptoms including persistent sadness, fatigue, dysphoria, as well as disturbances in cognition, emotion, appetite, and sleep. The main pathology behind PPD is the postpartum reduction of neurosteroids, referred to as neurosteroid withdrawal, a concept pioneered by our preclinical studies. We developed neurosteroid replacement therapy (NRT) as a rational approach for treating PPD and other conditions related to neurosteroid deficiency, unveiling the power of neurosteroids as novel anxiolytic-antidepressants. The neurosteroid, brexanolone (BX), is a progesterone-derived allopregnanolone that rapidly relieves anxiety and mood deficits by activating GABA-A receptors, making it a transformational treatment for PPD. In 2019, the FDA approved BX, an intravenous formulation of allopregnanolone, as an NRT to treat PPD. In clinical studies, BX significantly improved PPD symptoms within hours of administration, with tolerable side effects including headache, dizziness, and somnolence. We identified the molecular mechanism of BX in a neuronal PPD-like milieu. The mechanism of BX involves activation of both synaptic and extrasynaptic GABA-A receptors, which promote tonic inhibition and serve as a key target for PPD and related conditions. Neurosteroids offer several advantages over traditional antidepressants, including rapid onset, unique mechanism, and lack of tolerance upon repeated use. Some limitations of BX therapy include lack of aqueous solubility, limited accessibility, hospitalization for treatment, lack of oral product, and serious adverse events at high doses. However, the unmet need for synthetic neurosteroids to address this critical condition supersedes these limitations. Recently, we developed novel hydrophilic neurosteroids with a superior profile and improved drug delivery. Overall, approval of BX is a major milestone in the field of neurotherapeutics, paving the way for the development of novel synthetic neurosteroids to treat depression, epilepsy, and status epilepticus.

Menopause and Mood: The Role of Estrogen in Midlife Depression and Beyond

Depression is a disabling condition that often leads to significant burden. Women are more vulnerable to depression during reproductive-related "windows of vulnerability" such as the menopause transition and early postmenopausal years. This heightened vulnerability can be attributed, at least in part, to the neuromodulatory effects of estrogen on mood and cognition and the exposure to rapid fluctuations of estradiol levels during midlife years. The management of midlife depression can be challenging due to the presence and severity of other complaints such as vasomotor symptoms and sleep disturbances. Psychopharmacologic, behavioral, and hormonal interventions should be part of the treatment armamentarium.

Gestational stress decreases postpartum mitochondrial respiration in the prefrontal cortex of female rats

Postpartum depression (PPD) is a major psychiatric complication of childbirth, affecting up to 20% of mothers, yet remains understudied. Mitochondria, dynamic organelles crucial for cell homeostasis and energy production, share links with many of the proposed mechanisms underlying PPD pathology. Brain mitochondrial function is affected by stress, a major risk factor for development of PPD, and is linked to anxiety-like and social behaviors. Considering the importance of mitochondria in regulating brain function and behavior, we hypothesized that mitochondrial dysfunction is associated with behavioral alterations in a chronic stress-induced rat model of PPD. Using a validated and translationally relevant chronic mild unpredictable stress paradigm during late gestation, we induced PPD-relevant behaviors in adult postpartum Wistar rats. In the mid-postpartum, we measured mitochondrial function in the prefrontal cortex (PFC) and nucleus accumbens (NAc) using high-resolution respirometry. We then measured protein expression of mitochondrial complex proteins and 4-hydroxynonenal (a marker of oxidative stress), and Th1/Th2 cytokine levels in PFC and plasma. We report novel findings that gestational stress decreased mitochondrial function in the PFC, but not the NAc of postpartum dams. However, in groups controlling for the effects of either stress or parity alone, no differences in mitochondrial respiration measured in either brain regions were observed compared to nulliparous controls. This decrease in PFC mitochondrial function in stressed dams was accompanied by negative behavioral consequences in the postpartum, complex-I specific deficits in protein expression, and increased Tumor Necrosis Factor alpha cytokine levels in plasma and PFC. Overall, we report an association between PFC mitochondrial respiration, PPD-relevant behaviors, and inflammation following gestational stress, highlighting a potential role for mitochondrial function in postpartum health.

Zuranolone for the Treatment of Adults With Major Depressive Disorder: A Randomized, Placebo-Controlled Phase 3 Trial

OBJECTIVE

This study assessed the efficacy and safety of a 14-day treatment course of once-daily zuranolone 50 mg, an investigational oral positive allosteric modulator of the γ-aminobutyric acid type A (GABAA) receptor, for the treatment of major depressive disorder.

METHODS

Patients 18-64 years of age with severe major depressive disorder were enrolled in this randomized, double-blind, placebo-controlled trial. Patients self-administered zuranolone 50 mg or placebo once daily for 14 days. The primary endpoint was change from baseline in total score on the 17-item Hamilton Depression Rating Scale (HAM-D) at day 15. Safety and tolerability were assessed by incidence of adverse events.

RESULTS

Of 543 randomized patients, 534 (266 in the zuranolone group, 268 in the placebo group) constituted the full analysis set. Compared with patients in the placebo group, patients in the zuranolone group demonstrated a statistically significant improvement in depressive symptoms at day 15 (least squares mean change from baseline HAM-D score, -14.1 vs. -12.3). Numerically greater improvements in depressive symptoms for zuranolone versus placebo were observed by day 3 (least squares mean change from baseline HAM-D score, -9.8 vs. -6.8), which were sustained at all visits throughout the treatment and follow-up periods of the study (through day 42, with the difference remaining nominally significant through day 12). Two patients in each group experienced a serious adverse event; nine patients in the zuranolone group and four in the placebo group discontinued treatment due to adverse events.

CONCLUSIONS

Zuranolone at 50 mg/day elicited a significantly greater improvement in depressive symptoms at day 15, with a rapid time to effect (day 3). Zuranolone was generally well tolerated, with no new safety findings compared with previously studied lower dosages. These findings support the potential of zuranolone in treating adults with major depressive disorder.

Safety of Brexanolone in Adults with Postpartum Depression: Postmarketing Surveillance Data

BACKGROUND

Brexanolone is currently the only medication approved by the US FDA for the treatment of postpartum depression (PPD) in patients ≥15 years. Brexanolone is available commercially only through a restricted program (ZULRESSO® Risk Evaluation and Mitigation Strategy; REMS) due to risk of excessive sedation or sudden loss of consciousness during administration.

OBJECTIVE

The aim of this analysis was to assess the postmarketing safety of brexanolone in adults with PPD.

METHODS

The cumulative postmarketing adverse event (AE) listing from spontaneous and solicited individual case safety reports (ICSRs) received from March 19, 2019, through December 18, 2021, was analyzed. Clinical trial ICSRs were excluded. Reported AEs were classified as serious or nonserious as defined by FDA seriousness criteria and as listed or unlisted based on Table 2.0 within section 6 "Adverse Reactions" of the current brexanolone FDA-approved US Prescribing Information (PI).

RESULTS

Overall, 499 patients received brexanolone in this postmarketing surveillance analysis between June 2019 and December 2021 (postmarketing setting). There were 137 ICSRs with 396 total AEs: 15 serious unlisted, 2 serious listed, 346 nonserious unlisted, and 33 nonserious listed. In total, two serious and one nonserious listed excessive sedation AEs were reported-all resolved by stopping infusion and did not require any treatment; no loss of consciousness AEs were received.

CONCLUSION

Results from postmarketing surveillance data analysis are consistent with the safety profile of brexanolone for the treatment of PPD as described in the FDA-approved PI. No new safety concerns or new aspects of known risks requiring an update to the FDA-approved PI were identified.

Perinatal Depression: A Review and an Update

Perinatal depression is a common psychiatric condition that has negative effects on pregnancy and infant outcomes. Screening for the condition is relatively easy and should be done routinely in all medical care of the pregnant and postpartum woman and her infant. The risk-benefit analysis favors the use of antidepressant medications during pregnancy and lactation compared with the risk of untreated maternal depression. Other, nonpharmacological treatments will be discussed as well as new treatments, including a new class of medications that act on the inhibitory GABAergic neurotransmitter system.

Zuranolone for the Treatment of Postpartum Depression

OBJECTIVE

Postpartum depression (PPD) is a common perinatal complication with adverse maternal and infant outcomes. This study investigated the efficacy and safety of zuranolone, a positive allosteric modulator of synaptic and extrasynaptic GABAA receptors and neuroactive steroid, as an oral, once-daily, 14-day treatment course for patients with severe PPD.

METHODS

In this double-blind phase 3 trial, women with severe PPD were randomized in a 1:1 ratio to receive zuranolone 50 mg/day or placebo for 14 days. The primary endpoint was change from baseline in total score on the 17-item Hamilton Depression Rating Scale (HAM-D) at day 15; key secondary endpoints were change from baseline in HAM-D score at days 3, 28, and 45 and change from baseline in Clinical Global Impressions severity (CGI-S) score at day 15. Adverse events were monitored.

RESULTS

Among 196 patients randomized (zuranolone, N=98; placebo, N=98), 170 (86.7%) completed the 45-day study. Treatment with zuranolone compared with placebo resulted in statistically significant improvement in depressive symptoms at day 15 (least squares mean [LSM] change from baseline in HAM-D score, -15.6 vs. -11.6; LSM difference, -4.0, 95% CI=-6.3, -1.7); significant improvement in depressive symptoms was also reported at days 3, 28, and 45. CGI-S score at day 15 significantly improved with zuranolone compared with placebo. The most common adverse events (≥10%) with zuranolone were somnolence, dizziness, and sedation. No loss of consciousness, withdrawal symptoms, or increased suicidal ideation or behavior were observed.

CONCLUSIONS

In this trial, zuranolone demonstrated significant improvements in depressive symptoms and was generally well tolerated, supporting the potential of zuranolone as a novel, rapid-acting oral treatment for PPD.

Neurosteroid influence on affective tone

Affective disorders such as depression and anxiety are among the most prevalent psychiatric illnesses and causes of disability worldwide. The recent FDA-approval of a novel antidepressant treatment, ZULRESSO® (Brexanolone), a synthetic neurosteroid has fueled interest into the role of neurosteroids in the pathophysiology of depression as well as the mechanisms mediating the antidepressant effects of these compounds. The majority of studies examining the impact of neurosteroids on affective states have relied on the administration of exogenous neurosteroids; however, neurosteroids can also be synthesized endogenously from cholesterol or steroid hormone precursors. Despite the well-established influence of exogenous neurosteroids on affective states, we still lack an understanding of the role of endogenous neurosteroids in modulating affective tone. This review aims to summarize the current literature supporting the influence of neurosteroids on affective states in clinical and preclinical studies, as well as recent evidence suggesting that endogenous neurosteroids may set a baseline affective tone.