Hormonal regulation of circuit function: sex, systems and depression

Emerging strategies and clinical recommendations for the management of novel depression subtypes

INTRODUCTION

The phenomenology of depression is characterized by a wide array of emotional, cognitive, and physical symptoms that significantly disrupt an individual's life. Societal changes, driven by technological advancements, economic pressures, environmental concerns including climate change, and shifting cultural norms, have influenced how depression manifests and is understood. These developments have led to the identification of new depression subtypes, highlighting the need for personalized treatment approaches based on individual symptoms and underlying causes.

AREAS COVERED

The authors provide a comprehensive narrative review of the literature on managing novel depression subtypes, focusing on both pharmacological and non-pharmacological treatments. Specifically, scenarios recorded were related to i) depression in adolescents and young adults; ii) depression and social disconnection; iii) depression and alcohol/substance use disorder; iv) depression and gender dysphoria; v) depression, stressful events, and other environmental factors.

EXPERT OPINION

In the novel depression subtypes discussed, individualized treatment approaches tailored to the individual's specific circumstances are necessary. While selective serotonin reuptake inhibitors (SSRIs) and serotonin and noradrenaline reuptake inhibitors (SNRIs) remain the cornerstone of treatment for many forms of depression, atypical antidepressants such as trazodone, and emerging therapies like ketamine, neuromodulation techniques, and personalized psychotherapy offer hope for those with complex or treatment-resistant presentations.

Global trends of depressive disorders among women of reproductive age from 1990 to 2021: a systematic analysis of burden, sociodemographic disparities, and health workforce correlations

BACKGROUND

Depressive disorders significantly impact women of reproductive age (15-49 years), who face unique biological and social pressures-such as hormonal changes and caregiving responsibilities-that elevate their mental health risks. Despite rising prevalence, regional disparities in burden remain poorly understood. Moreover, no studies to date have examined the relationship between depressive disorders in women of reproductive age and different categories of health workforce. This study examines global, regional, and national trends from 1990 to 2021, highlighting socio-demographic disparities and exploring correlations with health workforce distribution.

METHODS

Using data from the Global Burden of Disease Study, we examined the prevalence, incidence, and disability-adjusted life years (DALYs) of depression in women of childbearing age (15-49 years) across 204 countries and territories from 1990 to 2021. Long-term trends were assessed through estimated annual percentage change (EAPC), while decomposition analyses identified drivers of disease burden changes. We also analyzed correlations between depressive disorder burden and various health workforce categories using data from the GBD 2019 Health Workforce Collaborators.

RESULTS

From 1990 to 2021, the global prevalence of depression in women of reproductive age rose by 67.58%, incidence by 71.44%, and DALYs by 69.08%. Notably, this burden increased dramatically during the COVID-19 pandemic, with prevalence rising by 17.86%, incidence by 24.51%, and DALYs by 20.80% between 2019-2021 alone. Regions with low sociodemographic index (SDI) saw the largest increase in absolute cases (157.80% for prevalence), while high SDI regions experienced the fastest rise in age-standardized rates (32.45% for prevalence). Among all SDI levels, the 15-19 age group exhibited the greatest increase. Decomposition analyses indicated that population growth primarily drove the increased disease burden, though epidemiological changes played a larger role in high SDI regions. Our analysis revealed significant correlations between depressive disorder burden and health workforce distribution. Notably, countries with high depressive disorder burden, such as Georgia, might benefit from increasing the number of Audiologists and Counsellors while optimizing the role of Medical Assistants and Community Health Workers in detection and referral.

CONCLUSION

The global burden of depression among women of childbearing age is increasing significantly, with a marked acceleration during the COVID-19 pandemic period. Notable disparities exist across regions and age groups, with differential impacts in pre-pandemic versus pandemic timeframes. The correlations between health workforce categories and depressive disorder burden underscore the need for targeted interventions and resource allocation. These findings highlight the urgent need for strengthened prevention and intervention efforts, particularly those tailored to socioeconomic differences and focused on this vulnerable population, with special attention to pandemic-related mental health challenges.

A PRISMA Systematic Review of Sexual Dysfunction and Probiotics with Pathophysiological Mechanisms

Sexual dysfunction, influenced by hormonal imbalances, psychological factors, and chronic diseases, affects a significant portion of the population. Probiotics, known for their beneficial effects on gut microbiota, have emerged as potential therapeutic agents for improving sexual health. This systematic review evaluates the impact of probiotics on sexual function, hormonal regulation, and reproductive outcomes. A comprehensive search identified 3308 studies, with 12 meeting the inclusion criteria-comprising 10 randomized controlled trials (RCTs) and 2 in vivo and in vitro studies. Probiotic interventions were shown to significantly improve sexual function, particularly in women undergoing antidepressant therapy (p < 0.05). Significant improvements in Female Sexual Function Index (FSFI) scores were observed, with combined treatments such as Lactofem with Letrozole and Lactofem with selective serotonin reuptake inhibitors (SSRIs) demonstrating a 10% biochemical and clinical pregnancy rate compared to 0% in the control group (p = 0.05). Probiotic use was also associated with a 66% reduction in menopausal symptoms, increased sperm motility (36.08%), viability (46.79%), and morphology (36.47%). Probiotics also contributed to favorable hormonal changes, including a reduced luteinizing hormone (LH) to follicle-stimulating hormone (FSH) ratio (from 3.0 to 2.5, p < 0.05) and increased testosterone levels. Regarding reproductive outcomes, probiotic use was associated with higher pregnancy rates in women undergoing fertility treatments and improvements in sperm motility, viability, and morphology in men. This review highlights the promising role of probiotics in addressing sexual dysfunction and reproductive health, suggesting their potential as adjunctive treatments for conditions such as depression and infertility. Further research is needed to better understand the underlying mechanisms of these beneficial effects.

A study on the differences in the gut microbiota and metabolism between male and female mice in different stress periods

The sex difference in depression has long been an unsolved issue. Women are twice as likely to suffer from depression as men. However, there were significant differences in the composition of gut microbiota between women and men. There is a lack of studies linking sex differences in depression to microbiota, and the specific mechanisms of this process have not been explained in detail. The main purpose of this study was to explore the gender differences in the intestinal tract of male and female depressed mice. In this study, chronic restraint stress (CRS) mouse models were used to simulate chronic stress, and behavioral tests were conducted, including the open field test (OFT), tail suspension test (TST) and forced swimming test (FST). Microbial diversity analysis and metabolomics were performed on collected mouse feces. The results showed that female mice were highly active and prone to anxious behavior before stress, and the levels of f-Rikenellaceae, f-Ruminococcaceae and 16α-hydroxyestrone were significantly different from those in male mice. After 21 days (Days) of stress, female mice showed depression-like behavior, and the levels of f-Erysipelotrichaceae, 5α-pregnane-3,20-dione, and 2-hydroxyestradiol were significantly different from those in male mice. After 14 days of stress withdrawal, the depression-like behavior continued to worsen in female mice, and the levels of 5α-pregnane-3,20-dione, estrone glucuronide and f-Erysipelotrichaceae were significantly different from those in male mice. In summary, female mice have stronger stress sensitivity and weaker resilience than male mice, which may be related to differences in bacterial diversity and estrogen metabolism disorders.

A predictive model for depression risk in individuals with hypertension: evidence from NHANES 2007-2020

OBJECTIVE

Hypertension increases the prevalence of depression to a certain extent and identification and diagnosis of depression frequently pose challenges for clinicians. The study aimed to construct and validate a scoring model predicting the prevalence of depression with hypertension.

METHODS

6124 individuals with hypertension were utilized from the 2007 to 2020 National Health and Nutrition Examination Survey database (NHANES), including 645 subjects that were assessed to have depressive symptoms, 390 in the development group and 255 in the validation group. Univariable and multivariable analyses were applied to analyze the impact of each parameter on depression with hypertension, resulting in establishment of a predictive model. Finally, the discriminability, calibration ability, and clinical efficacy of the model were verified for both the derivation set and validation set.

RESULTS

Ten variables comprised this model: age, gender, race, poverty to income ratio (PIR), smoke, sleep hours, exercise, diabetes, congestive heart failure, stroke. The area under the receiver operating characteristic curve for the derivation and validating sets was 0.790 and 0.723, respectively, which showed excellent discriminability. The model also fitted well with the actual prevalence of depression with hypertension in calibration and decision curve analysis (DCA) demonstrated that the depression model was practically useful.

CONCLUSION

This scoring model may provide an additional perspective for evaluating the underlying risk factors of depression for hypertensive individuals.

Gut feeling: Exploring the intertwined trilateral nexus of gut microbiota, sex hormones, and mental health

The complex interplay between the gut microbiota, sex hormones, and mental health is emerging as a pivotal factor in understanding and managing psychiatric disorders. Beyond their traditional roles, sex hormones exert profound effects on various physiological systems including the gut microbiota. Fluctuations in sex hormone levels, notably during the menstrual cycle, influence gut physiology and barrier function, shaping gut microbiota composition and immune responses. Conversely, the gut microbiota actively modulates sex hormone levels via enzymatic processes. This bidirectional relationship underscores the significance of the gut-brain axis in maintaining mental well-being. This review explores the multifaceted interactions between sex hormones, the gut microbiota, and mental health outcomes. We highlight the potential of personalized interventions in treating psychiatric disorders, particularly in vulnerable populations such as premenopausal women and individuals with depressive disorders. By elucidating these complex interactions, we aim to provide insights for future research into targeted interventions, enhancing mental health outcomes.

Association between Enhanced Effective Connectivity from the Cuneus to the Middle Frontal Gyrus and Impaired Alertness after Total Sleep Deprivation

BACKGROUND

Sleep deprivation (SD) can impair an individual's alertness, which is the basis of attention and the mechanism behind continuous information processing. However, research concerning the effects of total sleep deprivation (TSD) on alertness networks is inadequate. In this study, we investigate the cognitive neural mechanism of alertness processing after TSD.

METHODS

Twenty-four college students volunteered to participate in the study. The resting-state electroencephalogram (EEG) data were collected under two conditions (rested wakefulness [RW], and TSD). We employed isolated effective coherence (iCoh) analysis and functional independent component analysis (fICA) to explore the effects of TSD on participants' alertness network.

RESULTS

This study found the existence of two types of effective connectivity after TSD, as demonstrated by iCoh: from the left cuneus to the right middle frontal gyrus in the β3 and γ bands, and from the left angular gyrus to the left insula in the δ, θ, α, β1, β3, and γ bands. Furthermore, Pearson correlation analysis showed that increased effective connectivity between all the bands had a positive correlation with increases in the response time in the psychomotor vigilance task (PVT). Finally, fICA revealed that the neural oscillations of the cuneus in the α2 bands increased, and of the angular gyrus in the α and β1 bands decreased in TSD.

CONCLUSIONS

TSD impairs the alertness function among individuals. Increased effective connectivity from the cuneus to the middle frontal gyrus may represent overloads on the alertness network, resulting in participants strengthening top-down control of the attention system. Moreover, enhanced effective connectivity from the angular gyrus to the insula may indicate a special perception strategy in which individuals focus on salient and crucial environmental information while ignoring inessential stimuli to reduce the heavy burden on the alertness network.

CLINICAL TRIAL REGISTRATION

No: ChiCTR2400088448. Registered 19 August 2024, https://www.chictr.org.cn.

An integrated machine learning framework for developing and validating a diagnostic model of major depressive disorder based on interstitial cystitis-related genes

BACKGROUND

Major depressive disorder (MDD) and interstitial cystitis (IC) are two highly debilitating conditions that often coexist with reciprocal effect, significantly exacerbating patients' suffering. However, the molecular underpinnings linking these disorders remain poorly understood.

METHODS

Transcriptomic data from GEO datasets including those of MDD and IC patients was systematically analyzed to develop and validate our model. Following removal of batch effect, differentially expressed genes (DEGs) between respective disease and control groups were identified. Shared DEGs of the conditions then underwent functional enrichment analyses. Additionally, immune infiltration analysis was quantified through ssGSEA. A diagnostic model for MDD was constructed by exploring 113 combinations of 12 machine learning algorithms with 10-fold cross-validation on the training sets following by external validation on test sets. Finally, the "Enrichr" platform was utilized to identify potential drugs for MDD.

RESULTS

Totally, 21 key genes closely associated with both MDD and IC were identified, predominantly involved in immune processes based on enrichment analyses. Immune infiltration analysis revealed distinct profiles of immune cell infiltration in MDD and IC compared to healthy controls. From these genes, a robust 11-gene (ABCD2, ATP8B4, TNNT1, AKR1C3, SLC26A8, S100A12, PTX3, FAM3B, ITGA2B, OLFM4, BCL7A) diagnostic signature was constructed, which exhibited superior performance over existing MDD diagnostic models both in training and testing cohorts. Additionally, epigallocatechin gallate and 10 other drugs emerged as potential targets for MDD.

CONCLUSION

Our work developed a diagnostic model for MDD employing a combination of bioinformatic techniques and machine learning methods, focusing on shared genes between MDD and IC.

Do the Gender and the Number of Comorbidities and the Use of Tertiary Prevention Play a Role in the Severity of Anxiety and Depression in Patients with Coronary Artery Disease? A POLASPIRE II Study

Background/Objectives: The need to conduct research on anxiety and depression in patients with coronary artery disease in connection with factors such as gender or implemented tertiary prevention is very important for drawing practical conclusions and, consequently, implementing new recommendations and procedures. The aim of the study was to attempt to answer the question whether gender and the number of comorbidities, as well as the application of tertiary prevention principles, play a role in the severity of anxiety and depression in the studied group of patients with coronary artery disease. Material: The study involved 765 patients from 11 Polish cardiology centers. The presented material is part of the multicenter POLASPIRE II study. Methods: All patients completed The Hospital Anxiety and Depression Scale (HADS) questionnaire, and a medical interview was conducted with them. Conclusions: Although the intensity of anxiety and depression in the studied group of patients was low, gender differentiated them, which, however, did not influence undertaking tertiary prevention activities. In the study group of patients, the number of comorbidities and cardiac incidents/procedures after the event qualifying for the study, as well as preventive actions undertaken, were not associated with the severity of anxiety and depression. In the studied group of patients with coronary heart disease, there was still a large group of people who did not take preventive measures. Therefore, there is a need for systematic education regarding the benefits of implementing them to prevent the progression of the disease and premature death.

Explaining how childhood physical abuse and physical neglect influence adult depression: An analysis with multiple sequential mediators

BACKGROUND

Substantial evidence indicates that experiencing physical abuse and neglect during childhood significantly elevates the likelihood of developing depression in adulthood. Nevertheless, there remains a dearth of understanding regarding the mechanisms underpinning this correlation.

OBJECTIVE

In this study, we aimed to examine the associations of childhood physical abuse and physical neglect with depression using follow-up data from UK Biobank and quantified the contribution of smoking, insomnia, and BMI in these associations.

PARTICIPANTS AND SETTINGS

This study included 144,704 participants (64,168 men and 80,536 women) from UK Biobank, most of whom were white (97 %).

METHODS

Physical abuse and physical neglect were measured using two items of Childhood Trauma Screener (CTS). Data on the incidence of depression were obtained from primary care, hospital inpatient records, self-reported medical conditions, and death registries. We used a sequential mediation analysis based on the "g-formula" approach to explore the individual and joint effects of potential mediators.

RESULTS

The depression incidence rate was 1.85 per 1000 person-years for men and 2.83 per 1000 person-years for women, respectively. Results of Cox proportional risk regression showed that physical abuse (HRs: 1.39-1.53, P < 0.001) and physical neglect (HRs: 1.43-1.60, P < 0.001) are associated with depression. Smoking, insomnia, and BMI together mediated 3 %-26 % of the associations.

CONCLUSIONS

These findings contribute to our understanding of how physical abuse and physical neglect influence depression. Furthermore, a more effective reduction in the burden of depression can be achieved by managing modifiable mediators.

Positive Effect of 6-Gingerol on Functional Plasticity of Microglia in a rat Model of LPS-induced Depression

Neuroinflammation has emerged as a crucial factor in the development of depression. Despite the well-known anti-inflammatory properties of 6-gingerol, its potential impact on depression remains poorly understood. This study aimed to investigate the antidepressant effects of 6-gingerol by suppressing microglial activation. In vivo experiments were conducted to evaluate the effect of 6-gingerol on lipopolysaccharide (LPS)-induced behavioral changes and neuroinflammation in rat models. In vitro studies were performed to examine the neuroprotective properties of 6-gingerol against LPS-induced microglial activation. Furthermore, a co-culture system of microglia and neurons was established to assess the influence of 6-gingerol on the expression of synaptic-related proteins, namely synaptophysin (SYP) and postsynaptic density protein 95 (PSD95), which are influenced by microglial activation. In the in vivo experiments, administration of 6-gingerol effectively alleviated LPS-induced depressive behavior in rats. Moreover, it markedly suppressed the activation of rat prefrontal cortex (PFC) microglia induced by LPS and the activation of the NF-κB/NLRP3 inflammatory pathway, while also reducing the levels of inflammatory cytokines IL-1β and IL-18. In the in vitro experiments, 6-gingerol mitigated nuclear translocation of NF-κB p65, NLRP3 activation, and maturation of IL-1β and IL-18, all of which were induced by LPS. Furthermore, in the co-culture system of microglia and neurons, 6-gingerol effectively restored the decreased expression of SYP and PSD95. The findings of this study demonstrate the neuroprotective effects of 6-gingerol in the context of LPS-induced depression-like behavior. These effects are attributed to the inhibition of microglial hyperactivation through the suppression of the NF-κB/NLRP3 inflammatory pathway.

Construction of a depression risk prediction model for type 2 diabetes mellitus patients based on NHANES 2007-2014

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a prevalent global health issue that has been linked to an increased risk of depression. The objective of this study was to construct a nomogram model for predicting depression in T2DM patients.

METHODS

A total of 4280 patients with T2DM were included in this study from the 2007-2014 NHANES. The entire dataset was split randomly into training set comprising 70 % of the data and a validation set comprising 30 % of the data. LASSO and multivariate logistic regression analyses identified predictors significantly associated with depression, and the nomogram was constructed with these predictors. The model was assessed by C-index, calibration curve, the hosmer-lemeshow test and decision curve analysis (DCA).

RESULTS

The nomogram model comprised of 9 predictors, namely age, gender, PIR, BMI, education attainment, smoking status, LDL-C, sleep duration and sleep disorder. The C-index of the training set was 0.780, while that of the validation set was 0.752, indicating favorable discrimination for the model. The model exhibited excellent clinical applicability and calibration in both the training and validation datasets. Moreover, the cut-off value of the nomogram is 223.

LIMITATIONS

This study has shortcomings in data collection, lack of external validation, and results non-extrapolation.

CONCLUSIONS

Our nomogram exhibits high clinical predictability, enabling clinicians to utilize this tool in identifying high-risk depressed patients with T2DM. It has the potential to decrease the incidence of depression and significantly improve the prognosis of patients with T2DM.

Depressive symptoms among adults: Baseline findings of PURE Malaysia cohort study

Introduction

In Malaysia, the prevalence of depression has increased from 1.8 % to 2.3 % within a decade. Thus, this study was performed to identify depressive symptoms and its associated factors among Malaysian adults.

Methods

A cross-sectional study was conducted among the adult population aged 35-70 residing in rural and urban areas in Malaysia. Depressive symptoms were assessed using the short form Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) Composite International Diagnostic Interview (CIDI) questionnaire. Logistic regression models were fitted to identify the associated factors related to depressive symptoms.

Results

About 3.7 % (95 % CI: 2.33-4.83) of the respondents reported having depressive symptoms. Younger adults aged 35-40 years old (AOR: 3.087; 95 % CI: 2.021-4.717), females (AOR: 2.318; 95 % CI: 1.669-3.219), widows and divorcees (AOR: 2.294; 95 % CI: 1.085-4.848), smokers (AOR: 1.843; 95 % CI: 1.334-2.545) and alcohol consumers (AOR: 1.843; 95 % CI: 1.264-2.688) showed a higher odds compared to their other counterparts. Underweight individuals (AOR: 1.899; 95 % CI: 1.177-3.065) and those diagnosed either with hypertension (AOR: 1.442; 95 % CI: 1.11-1.873), diabetes (AOR: 1.554; 95 % CI: 1.133-2.13), angina (AOR: 2.73; 95 % CI: 1.596-4.67), COPD (AOR: 4.187; 95 % CI: 1.528-11.472) or asthma (AOR: 1.906; 95 % CI: 1.309-2.774) were more likely to have depressive symptoms. Additionally, individuals with difficulty trusting people (AOR: 1.477; 95 % CI: 1.024-2.13) and those reported to experience either home or work-related stress (AOR: 2.584; 95 % CI: 2.003-3.331) were more prone to have depressive symptoms.

Conclusion

In this broad population-based study, about 3.7 % (95 % CI: 2.33-4.83) of respondents reported having depressive symptoms. Timely and well targeted collaborative intervention on the identified risk factors by the relevant authorities, would mitigate their effect on the quality of life and retard the progression into depression, especially among younger adults.

Prediction of brain sex from EEG: using large-scale heterogeneous dataset for developing a highly accurate and interpretable ML model

This study presents a comprehensive examination of sex-related differences in resting-state electroencephalogram (EEG) data, leveraging two different types of machine learning models to predict an individual's sex. We utilized data from the Two Decades-Brainclinics Research Archive for Insights in Neurophysiology (TDBRAIN) EEG study, affirming that gender prediction can be attained with noteworthy accuracy. The best performing model achieved an accuracy of 85% and an ROC AUC of 89%, surpassing all prior benchmarks set using EEG data and rivaling the top-tier results derived from fMRI studies. A comparative analysis of LightGBM and Deep Convolutional Neural Network (DCNN) models revealed DCNN's superior performance, attributed to its ability to learn complex spatial-temporal patterns in the EEG data and handle large volumes of data effectively. Despite this, interpretability remained a challenge for the DCNN model. The LightGBM interpretability analysis revealed that the most important EEG features for accurate sex prediction were related to left fronto-central and parietal EEG connectivity. We also showed the role of both low (delta and theta) and high (beta and gamma) activity in the accurate sex prediction. These results, however, have to be approached with caution, because it was obtained from a dataset comprised largely of participants with various mental health conditions, which limits the generalizability of the results and necessitates further validation in future studies. . Overall, the study illuminates the potential of interpretable machine learning for sex prediction, alongside highlighting the importance of considering individual differences in prediction sex from brain activity.

Electroencephalography findings in menstrually-related mood disorders: A critical review

The female reproductive years are characterized by fluctuations in ovarian hormones across the menstrual cycle, which have the potential to modulate neurophysiological and behavioral dynamics. Menstrually-related mood disorders (MRMDs) comprise cognitive-affective or somatic symptoms that are thought to be triggered by the rapid fluctuations in ovarian hormones in the luteal phase of the menstrual cycle. MRMDs include premenstrual syndrome (PMS), premenstrual dysphoric disorder (PMDD), and premenstrual exacerbation (PME) of other psychiatric disorders. Electroencephalography (EEG) non-invasively records in vivo synchronous activity from populations of neurons with high temporal resolution. The present overview sought to systematically review the current state of task-related and resting-state EEG investigations on MRMDs. Preliminary evidence indicates lower alpha asymmetry at rest being associated with MRMDs, while one study points to the effect being luteal-phase specific. Moreover, higher luteal spontaneous frontal brain activity (slow/fast wave ratio as measured by the delta/beta power ratio) has been observed in persons with MRMDs, while sleep architecture results point to potential circadian rhythm disturbances. In this review, we discuss the quality of study designs as well as future perspectives and challenges of supplementing the diagnostic and scientific toolbox for MRMDs with EEG.

Sex Determines Anterior Cingulate Cortex Cortical Thickness in the Course of Depression

Background

Major depressive disorder (MDD) is a severe psychiatric disorder affecting women more than men. Changes in anterior cingulate cortex cortical thickness (ACC CT) may be crucial to understanding sex influences in MDD onset and recurrency.

Methods

Taken from the large open-source REST-meta-MDD database, we contrasted 499 patients with MDD (381 first-episode MDD, 118 recurrent MDD) and 524 healthy control participants using linear mixed-effects models and normative modeling and investigated whether sex differences affected ACC CT and its subregions differently during the course of depressive illness.

Results

Overall, females showed thinner ACC CT compared with males. Female patients with a first depressive episode showed significantly thinner ACC CT compared with male patients with first-episode MDD (Cohen's d = -0.65), including in the perigenual ACC and the subgenual ACC, but not in the dorsal ACC. Moreover, male patients with first-episode depression showed thicker ACC CT (including subgenual ACC and pregenual ACC) compared to the male patients with recurrent MDD (Cohen's d = 1.24), but they also showed significantly thicker cortices in the same subregions in comparison to never-depressed males (Cohen's d = 0.85). No lateralization differences were observed in ACC CT or its subdivisions.

Conclusions

Sex determined ACC CT changes over the course of depressive illness. Because the ACC subdivisions in question are associated with dysregulation of emotions, our observations substantiate the need for early and prolonged sex-specific clinical interventions.

The sex differences in anhedonia in major depressive disorder: A resting-state fMRI study

OBJECTIVE

The external behavioural manifestations and internal neural mechanisms of anhedonia are sexually dimorphic. This study aimed to explore the sex differences in the regional brain neuroimaging features of anhedonia in the context of major depressive disorder (MDD).

METHOD

The resting-fMRI by applying amplitude of low-frequency fluctuation (ALFF) method was estimated in 414 patients with MDD (281 high anhedonia [HA], 133 low anhedonia [LA]) and 213 healthy controls (HC). The effects of two factors in patients with MDD were analysed using a 2 (sex: male, female) × 2 (group: HA, LA) ANOVA concerning the brain regions in which statistical differences were identified between patients with MDD and HC. We followed up with patients with HA at baseline, and 43 patients completed a second fMRI scan in remission. Paired t-test was performed to compare the ALFF values of anhedonia-related brain regions between the baseline and remission periods.

RESULTS

For the sex-by-group interaction, the bilateral insula, right hippocampus, right post cingulum cortex, and left putamen showed significant differences. Furthermore, the abnormally elevated ALFF values in anhedonia-related brain regions at baseline decreased in remission.

CONCLUSION

Our findings point to the fact that the females showed unique patterns of anhedonia-related brain activity compared to males, which may have clinical implications for interfering with the anhedonia symptoms in MDD. Using task fMRI, we can further examine the distinct characteristics between consumption anhedonia and anticipation anhedonia in MDD.

Causal relationship between sex hormone-binding globulin and major depression: A Mendelian randomization study

OBJECTIVE

This study aimed to explore the causal relationship between sex hormone-binding globulin (SHBG) and major depression using two-sample Mendelian randomization (MR) studies.

METHODS

Based on the genome-wide association study (GWAS) summary data of SHBG and major depression in the European population, which included 214,989 female SHBG samples, 185,221 male SHBG samples, and 500,199 major depression samples, we used genetic factors as instrumental variables to conduct two-sample MR analyses. We used methods including inverse variance weighted (IVW), weighted median, weighted mode, and MR Egger to evaluate the bidirectional causal relationship between SHBG and major depression.

RESULTS

The results showed that there was a causal relationship between female SHBG and major depression, which was positively correlated. The ORs were 1.056 (95% CI: 1.005-1.109, p = 0.031) for the weighted median and 1.067 (95% CI: 1.012-1.126, p = 0.021) for the weighted mode. There was no significant effect of male SHBG on major depression (p > 0.05), and there was no significant effect of major depression on female SHBG (p > 0.05). Major depression was negatively correlated with male SHBG, indicating that major depression could lead to a decrease in male SHBG. The OR was 0.954 (95% CI: 0.916-0.993, p = 0.023) for IVW.

CONCLUSION

Female SHBG was positively correlated with the risk of major depression, however, major depression was found to be negatively correlated with serum SHBG levels in men, indicating that SHBG plays distinct roles in patients with major depression of different genders.

Effect of total sleep deprivation on effective EEG connectivity for young male in resting-state networks in different eye states

Background

Many studies have investigated the effect of total sleep deprivation (TSD) on resting-state functional networks, especially the default mode network (DMN) and sensorimotor network (SMN), using functional connectivity. While it is known that the activities of these networks differ based on eye state, it remains unclear how TSD affects them in different eye states. Therefore, we aimed to examine the effect of TSD on DMN and SMN in different eye states using effective functional connectivity via isolated effective coherence (iCoh) in exact low-resolution brain electromagnetic tomography (eLORETA).

Methods

Resting-state electroencephalogram (EEG) signals were collected from 24 male college students, and each participant completed a psychomotor vigilance task (PVT) while behavioral data were acquired. Each participant underwent 36-h TSD, and the data were acquired in two sleep-deprivation times (rested wakefulness, RW: 0 h; and TSD: 36 h) and two eye states (eyes closed, EC; and eyes open, EO). Changes in neural oscillations and effective connectivity were compared based on paired t-test.

Results

The behavioral results showed that PVT reaction time was significantly longer in TSD compared with that of RW. The EEG results showed that in the EO state, the activity of high-frequency bands in the DMN and SMN were enhanced compared to those of the EC state. Furthermore, when compared with the DMN and SMN of RW, in TSD, the activity of DMN was decreased, and SMN was increased. Moreover, the changed effective connectivity in the DMN and SMN after TSD was positively correlated with an increased PVT reaction time. In addition, the effective connectivity in the different network (EO-EC) of the SMN was reduced in the β band after TSD compared with that of RW.

Conclusion

These findings indicate that TSD impairs alertness and sensory information input in the SMN to a greater extent in an EO than in an EC state.

Prevalence and risk factors for depression and anxiety in patients with nasolacrimal duct obstruction

Objective

To investigate the prevalence and risk factors for depression and anxiety in patients with nasolacrimal duct obstruction (NLDO).

Methods

We conducted a telephone-based survey of patients with NLDO who underwent dacryocystorhinostomy (DCR) at the Department of Ophthalmology of Peking University Third Hospital in China between January 2016 and January 2021. Depression and anxiety were assessed with the PHQ-9 (range 0-25) and STAI (range 20-80) scales. PHQ-9 ≥ 5 and STAI ≥ 55 were considered clinically significant. Logistic regression and linear regression were performed to determine the factors related to depression and anxiety.

Results

Of 565 patients approached, 344 (60.9%) completed the survey. A total of 13.1% of patients had mild-severe depression and 63.4% had severe anxiety. Univariate logistic regression revealed that hypertension, dry eye, and cataract were associated with mild to severe depression (P = 0.018, 0.045, 0.035, respectively). Dry eye was associated with severe anxiety (P = 0.007). Univariate linear regression revealed that male and income levels were significantly negatively correlated with PHQ-9 scores (P = 0.011, 0.010, respectively). Hypertension and dry eye were significantly positively correlated with PHQ-9 scores (P = 0.030, P < 0.001, respectively). Male, income levels, and educational levels were significantly negatively correlated with STAI scores (P = 0.022, P < 0.001, P = 0.005, respectively). Dry eye was significantly positively correlated with STAI scores (P < 0.001).

Conclusion

Prevalence of depression and anxiety disorders was relatively high among NLDO patients. Our results demonstrate the importance of depression and anxiety screening and psychosocial support for patients with NLDO, which can improve their quality of life and compliance with medical appointments.

Sex differences in comorbidities associated with Sjögren's disease

Background

Little is known about the association of comorbidities with sex and age at diagnosis in Sjögren's disease. We tested the hypothesis that sex differences occur in comorbidities in patients with Sjögren's disease.

Methods

Patients with Sjögren's disease were identified from 11/1974 to 7/2018 in the Mayo Clinic electronic medical record and assessed for 22 comorbidities according to sex and age at diagnosis.

Results

Of the 13,849 patients identified with Sjögren's disease, 11,969 (86%) were women and 1,880 (14%) men, primarily white (88%) with a sex ratio of 6.4:1 women to men. The mean age at diagnosis was 57 years for women and 59.7 years for men, and 5.6% had a diagnosis of fibromyalgia at Sjögren's diagnosis. Men with Sjögren's disease were more likely than women to be a current or past smoker. The average time to diagnosis of comorbidities after diagnosis of Sjögren's disease was 2.6 years. The top comorbidities in patients with Sjögren's disease were fibromyalgia (25%), depression (21.2%) and pain (16.4%). Comorbidities that occurred more often in women were hypermobile syndromes (31:1), CREST (29:1), migraine (23:1), Ehlers-Danlos syndrome (EDS) (22:1), Raynaud's syndrome (15:1), SLE (13:1), systemic sclerosis (SSc) (13:1), and fibromyalgia (12:1). Women with Sjögren's disease were at increased risk of developing hypermobile syndromes (RR 7.27, CI 1.00-52.71, p = 0.05), EDS (RR 4.43, CI 1.08-18.14, p = 0.039), CREST (RR 4.24, CI 1.56-11.50, p = 0.005), migraine (RR 3.67, CI 2.39-5.62, p < 0.001), fibromyalgia (RR 2.26, CI 1.92-2.66, p < 0.001), Raynaud's syndrome (RR 2.29, CI 1.77-2.96, p < 0.001), SLE (RR 2.13, CI 1.64-2.76, p < 0.001), and SSc (RR 2.05 CI 1.44-2.92; p < 0.001). In contrast, men with Sjögren's were at increased risk for developing myocardial infarction (RR 0.44, CI 0.35-0.55, p < 0.001), atherosclerosis/CAD (RR 0.44, CI 0.39-0.49, p < 0.001), cardiomyopathy (RR 0.63, CI 0.46-0.86, p = 0.003), stroke (RR 0.66 CI 0.51-0.85, p = 0.001), and congestive heart failure (RR 0.70, CI 0.57-0.85, p < 0.001).

Conclusions

The top comorbidities in Sjögren's disease were fibromyalgia, depression, and pain. Women with Sjögren's disease had a higher relative risk of developing fibromyalgia, depression, pain, migraine, hypermobile syndrome, EDS and other rheumatic autoimmune diseases. Men with Sjögren's disease had higher risk of developing cardiovascular diseases.

Smoking, Health Risks, Coping Mechanisms and Depression in the age of COVID-19: a cross-sectional study of the Lebanese Population

Introduction

We compared depression of people who smoke and those who do not, depending on whether they have an underlying disease making them at risk for COVID-19. Moreover, we analyzed the factors associated with their depression.

Methods

We recruited 948 Lebanese residents, ages 18 and above. Our survey included the Patient Health Questionnaire-9 (PHQ-9) to assess depression. We divided participants, based on smoking and having a disease making one at risk for a COVID19 infection into four groups: non-smokers not at risk (NSNR), non-smokers at risk (NSR), smokers not at risk (SNR), and smokers at risk (SR).

Results

SR had PHQ-9 scores higher than other groups. The diet was not changed during the pandemic, whereas weight increased in all groups but SR. Those not at risk slept longer, while sports were decreased in NSR and SNR. Hobbies were decreased in all groups except SNR. Depending on the group, factors such as age, sex, residency, diet, exercise, sleep duration, and hobbies were associated with PHQ-9 scores.

Limitations

we cannot draw causal relationships. Participation required internet access, and participants might not represent the actual population due to the snowball effect. Also, recall bias might skew results. We did not inquire about sexual activity, which could be an essential coping mechanism.

Conclusion

Factors associated with depression for one group did not necessarily do so for another. Controlling the underlying risk or smoking cessation could move a patient to a group with more options associated with depression, thereby additional methods to decrease depression.

Sexual Dimorphism in the Brain Correlates of Adult-Onset Depression: A Pilot Structural and Functional 3T MRI Study

Major Depressive Disorder (MDD) is a disabling illness affecting more than 5% of the elderly population. Higher female prevalence and sex-specific symptomatology have been observed, suggesting that biologically-determined dimensions might affect the disease onset and outcome. Rumination and executive dysfunction characterize adult-onset MDD, but sex differences in these domains and in the related brain mechanisms are still largely unexplored. The present pilot study aimed to explore any interactions between adult-onset MDD and sex on brain morphology and brain function during a Go/No-Go paradigm. We hypothesized to detect diagnosis by sex effects on brain regions involved in self-referential processes and cognitive control. Twenty-four subjects, 12 healthy (HC) (mean age 68.7 y, 7 females and 5 males) and 12 affected by adult-onset MDD (mean age 66.5 y, 5 females and 7 males), underwent clinical evaluations and a 3T magnetic resonance imaging (MRI) session. Diagnosis and diagnosis by sex effects were assessed on regional gray matter (GM) volumes and task-related functional MRI (fMRI) activations. The GM volume analyses showed diagnosis effects in left mid frontal cortex (p < 0.01), and diagnosis by sex effects in orbitofrontal, olfactory, and calcarine regions (p < 0.05). The Go/No-Go fMRI analyses showed MDD effects on fMRI activations in left precuneus and right lingual gyrus, and diagnosis by sex effects on fMRI activations in right parahippocampal gyrus and right calcarine cortex (p < 0.001, ≥ 40 voxels). Our exploratory results suggest the presence of sex-specific brain correlates of adult-onset MDD-especially in regions involved in attention processing and in the brain default mode-potentially supporting cognitive and symptom differences between sexes.

Sex differences in neuronal systems function and behaviour: beyond a single diagnosis in autism spectrum disorders

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder that is associated with functional brain alterations that underlie the expression of behaviour. Males are diagnosed up to four times more than females, and sex differences have been identified in memory, cognitive flexibility, verbal fluency, and social communication. Unfortunately, there exists a lack of information on the sex-dependent mechanisms of ASD, as well as biological markers to distinguish sex-specific symptoms in ASD. This can often result in a standardized diagnosis for individuals across the spectrum, despite significant differences in the various ASD subtypes. Alterations in neuronal connectivity and oscillatory activity, such as is observed in ASD, are highly coupled to behavioural states. Yet, despite the well-identified sexual dimorphisms that exist in ASD, these functional patterns have rarely been analyzed in the context of sex differences or symptomology. This review summarizes alterations in neuronal oscillatory function in ASD, discusses the age, region, symptom and sex-specific differences that are currently observed across the spectrum, and potential targets for regulating neuronal oscillatory activity in ASD. The need to identify sex-specific biomarkers, in order to facilitate specific diagnostic criteria and allow for more targeted therapeutic approaches for ASD will also be discussed.

Effectiveness of common antidepressants: a post market release study

BACKGROUND

This study summarizes the experiences of patients, who have multiple comorbidities, with 15 mono-treated antidepressants.

METHODS

This is a retrospective, observational, matched case control study. The cohort was organized using claims data available through OptumLabs for depressed patients treated with antidepressants between January 1, 2001 and December 31, 2018. The cohort included patients from all states within United States of America. The analysis focused on 3,678,082 patients with major depression who had 10,221,145 antidepressant treatments. Using the robust, and large predictors of remission, and propensity to prescribe an antidepressant, the study created 16,770 subgroups of patients. The study reports the remission rate for the antidepressants within the subgroups. The overall impact of antidepressant on remission was calculated as the common odds ratio across the strata.

FINDINGS

The study accurately modelled clinicians' prescription patterns (cross-validated Area under the Receiver Operating Curve, AROC, of 82.0%, varied from 77% to 90%) and patients' remission (cross-validated AROC of 72.0%, varied from 69.5% to 78%). In different strata, contrary to published randomized studies, remission rates differed significantly and antidepressants were not equally effective. For example, in age and gender subgroups, the best antidepressant had an average remission rate of 50.78%, 1.5 times higher than the average antidepressant (30.30% remission rate) and 20 times higher than the worst antidepressant. The Breslow-Day chi-square test for homogeneity showed that across strata a homogenous common odds-ratio did not exist (alpha<0.0001). Therefore, the choice of the optimal antidepressant depended on the strata defined by the patient's medical history.

INTERPRETATION

Study findings may not be appropriate for specific patients. To help clinicians assess the transferability of study findings to specific patient, the web site http://hi.gmu.edu/ad assesses the patient's medical history, finds similar cases in our data, and recommends an antidepressant based on the experience of remission in our data. Patients can share this site's recommendations with their clinicians, who can then assess the appropriateness of the recommendations.

FUNDING

This project was funded by the Robert Wood Johnson foundation grant #76786. The development of related web site was supported by grant 247-02-20 from Virginia's Commonwealth Health Research Board.

Depression in Ugandan Rural Women Involved in a Money Saving Group: The Role of Spouse's Unemployment, Extramarital Relationship, and Substance Use

Background

Rural women are highly prevalent to depression, where spouse-related factors, including extramarital affairs and poverty, intensify its likelihood of occurrence. However, women engaged with a Money-Saving Group (MSG) are financially self-dependent, which can reduce the risk of depression suffering. Despite this, there is less study among this cohort, which led us to investigate the prevalence and associated factors of depression among the Ugandan women involved in MSG.

Methods

This was a cross-sectional study in Uganda among rural married or cohabiting women aged 18 to 45 years engaged in MSG. The survey was carried out within a total of 153 participants (33.3 ± 6.7 years) in April 2021. Information related to socio-demographic of the participants, their spouse characteristics, and depression were collected.

Results

About 65.4% of the participants had depressive symptoms (based on the cutoff 10/27 at the PHQ-9). But, 8.15 times (CI: 2.83–23.44, p<0.001) and 16.69 times (CI: 4.85–57.39, p<0.001), higher risk of depression were observed, if the participants’ spouses were using an addictive substance and had been involved in an extramarital relationship, respectively. Similarly, there was an increased likelihood of depression when the participant or spouse was unemployed.

Conclusion

This study observed a higher prevalence of depression, which suggests paying attention to this cohort. Thus, there should be routine screening for depression among married women involved in MSG at lower-level health facilities in rural settings, especially those with spouses engaged in substance use, having an extramarital relationship, and being unemployed.

The Antidepressant-Like and Analgesic Effects of Kratom Alkaloids are accompanied by Changes in Low Frequency Oscillations but not ΔFosB Accumulation

Mitragyna speciosa (“kratom”), employed as a traditional medicine to improve mood and relieve pain, has shown increased use in Europe and North America. Here, the dose-dependent effects of a purified alkaloid kratom extract on neuronal oscillatory systems function, analgesia, and antidepressant-like behaviour were evaluated and kratom-induced changes in ΔFosB expression determined. Male rats were administered a low or high dose of kratom (containing 0.5 or 1 mg/kg of mitragynine, respectively) for seven days. Acute or repeated low dose kratom suppressed ventral tegmental area (VTA) theta oscillatory power whereas acute or repeated high dose kratom increased delta power, and reduced theta power, in the nucleus accumbens (NAc), prefrontal cortex (PFC), cingulate cortex (Cg) and VTA. The repeated administration of low dose kratom additionally elevated delta power in PFC, decreased theta power in NAc and PFC, and suppressed beta and low gamma power in Cg. Suppressed high gamma power in NAc and PFC was seen selectively following repeated high dose kratom. Both doses of kratom elevated NAc-PFC, VTA-NAc, and VTA-Cg coherence. Low dose kratom had antidepressant-like properties whereas both doses produced analgesia. No kratom-induced changes in ΔFosB expression were evident. These results support a role for kratom as having both antidepressant and analgesic properties that are accompanied by specific changes in neuronal circuit function. However, the absence of drug-induced changes in ΔFosB expression suggest that the drug may circumvent this cellular signaling pathway, a pathway known for its significant role in addiction.

Identification of Diagnostic Markers for Major Depressive Disorder Using Machine Learning Methods

Background

Major depressive disorder (MDD) is a global health challenge that impacts the quality of patients’ lives severely. The disorder can manifest in many forms with different combinations of symptoms, which makes its clinical diagnosis difficult. Robust biomarkers are greatly needed to improve diagnosis and to understand the etiology of the disease. The main purpose of this study was to create a predictive model for MDD diagnosis based on peripheral blood transcriptomes.

Materials and Methods

We collected nine RNA expression datasets for MDD patients and healthy samples from the Gene Expression Omnibus database. After a series of quality control and heterogeneity tests, 302 samples from six studies were deemed suitable for the study. R package “MetaOmics” was applied for systematic meta-analysis of genome-wide expression data. Receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic effectiveness of individual genes. To obtain a better diagnostic model, we also adopted the support vector machine (SVM), random forest (RF), k-nearest neighbors (kNN), and naive Bayesian (NB) tools for modeling, with the RF method being used for feature selection.

Results

Our analysis revealed six differentially expressed genes (AKR1C3, ARG1, KLRB1, MAFG, TPST1, and WWC3) with a false discovery rate (FDR) < 0.05 between MDD patients and control subjects. We then evaluated the diagnostic ability of these genes individually. With single gene prediction, we achieved a corresponding area under the curve (AUC) value of 0.63 ± 0.04, 0.67 ± 0.07, 0.70 ± 0.11, 0.64 ± 0.08, 0.68 ± 0.07, and 0.62 ± 0.09, respectively, for these genes. Next, we constructed the classifiers of SVM, RF, kNN, and NB with an AUC of 0.84 ± 0.09, 0.81 ± 0.10, 0.73 ± 0.11, and 0.83 ± 0.09, respectively, in validation datasets, suggesting that the SVM classifier might be superior for constructing an MDD diagnostic model. The final SVM classifier including 70 feature genes was capable of distinguishing MDD samples from healthy controls and yielded an AUC of 0.78 in an independent dataset.

Conclusion

This study provides new insights into potential biomarkers through meta-analysis of GEO data. Constructing different machine learning models based on these biomarkers could be a valuable approach for diagnosing MDD in clinical practice.

Insights into the Pathophysiology of Psychiatric Symptoms in Central Nervous System Disorders: Implications for Early and Differential Diagnosis

Different psychopathological manifestations, such as affective, psychotic, obsessive-compulsive symptoms, and impulse control disturbances, may occur in most central nervous system (CNS) disorders including neurodegenerative and neuroinflammatory diseases. Psychiatric symptoms often represent the clinical onset of such disorders, thus potentially leading to misdiagnosis, delay in treatment, and a worse outcome. In this review, psychiatric symptoms observed along the course of several neurological diseases, namely Alzheimer’s disease, fronto-temporal dementia, Parkinson’s disease, Huntington’s disease, and multiple sclerosis, are discussed, as well as the involved brain circuits and molecular/synaptic alterations. Special attention has been paid to the emerging role of fluid biomarkers in early detection of these neurodegenerative diseases. The frequent occurrence of psychiatric symptoms in neurological diseases, even as the first clinical manifestations, should prompt neurologists and psychiatrists to share a common clinico-biological background and a coordinated diagnostic approach.

Sex differences in innate and adaptive neural oscillatory patterns link resilience and susceptibility to chronic stress in rats

BACKGROUND

Major depressive disorder is a chronic illness with a higher incidence in women. Dysregulated neural oscillatory activity is an emerging mechanism thought to underlie major depressive disorder, but whether sex differences in these rhythms contribute to the development of symptoms is unknown.

METHODS

We exposed male and female rats to chronic unpredictable stress and characterized them as stress-resilient or stress-susceptible based on behavioural output in the forced swim test and the sucrose preference test. To identify sex-specific neural oscillatory patterns associated with stress response, we recorded local field potentials from the prefrontal cortex, cingulate cortex, nucleus accumbens and dorsal hippocampus throughout stress exposure.

RESULTS

At baseline, female stress-resilient rats innately exhibited higher theta coherence in hippocampal connections compared with stress-susceptible female rats. Following stress exposure, additional oscillatory changes manifested: stress-resilient females were characterized by increased dorsal hippocampal theta power and cortical gamma power, and stress-resilient males were characterized by a widespread increase in high gamma coherence. In stress-susceptible animals, we observed a pattern of increased delta and reduced theta power; the changes were restricted to the cingulate cortex and dorsal hippocampus in males but occurred globally in females. Finally, stress exposure was accompanied by the time-dependent recruitment of specific neural pathways, which culminated in system-wide changes that temporally coincided with the onset of depression-like behaviour.

LIMITATIONS

We could not establish causality between the electrophysiological changes and behaviours with the methodology we employed.

CONCLUSION

Sex-specific neurophysiological patterns can function as early markers for stress vulnerability and the onset of depression-like behaviours in rats.

Treatment-Resistant Depression Revisited: A Glimmer of Hope

Major Depressive Disorder (MDD) is a highly prevalent psychiatric disorder worldwide. It causes individual suffering, loss of productivity, increased health care costs and high suicide risk. Current pharmacologic interventions fail to produce at least partial response to approximately one third of these patients, and remission is obtained in approximately 30% of patients. This is known as Treatment-Resistant Depression (TRD). The burden of TRD exponentially increases the longer it persists, with a higher risk of impaired functional and social functioning, vast losses in quality of life and significant risk of somatic morbidity and suicidality. Different approaches have been suggested and utilized, but the results have not been encouraging. In this review article, we present new approaches to identify and correct potential causes of TRD, thereby reducing its prevalence and with it the overall burden of this disease entity. We will address potential contributory factors to TRD, most of which can be investigated in many laboratories as routine tests. We discuss endocrinological aberrations, notably, hypothalamic-pituitary-adrenal (HPA) axis dysregulation and thyroid and gonadal dysfunction. We address the role of Vitamin D in contributing to depression. Pharmacogenomic testing is being increasingly used to determine Single Nucleotide Polymorphisms in Cytochrome P450, Serotonin Transporter, COMT, folic acid conversion (MTHFR). As the role of immune system dysregulation is being recognized as potentially a major contributory factor to TRD, the measurement of C-reactive protein (CRP) and select immune biomarkers, where testing is available, can guide combination treatments with anti-inflammatory agents (e.g., selective COX-2 inhibitors) reversing treatment resistance. We focus on established and emerging test procedures, potential biomarkers and non-biologic assessments and interventions to apply personalized medicine to effectively manage treatment resistance in general and TRD specifically.

Programming changes of hippocampal miR-134-5p/SOX2 signal mediate the susceptibility to depression in prenatal dexamethasone-exposed female offspring

Depression is a neuropsychiatric disorder and has intrauterine developmental origins. This study aimed to confirm the depression susceptibility in offspring rats induced by prenatal dexamethasone exposure (PDE) and to further explore the intrauterine programming mechanism. Wistar rats were injected with dexamethasone (0.2 mg/kg·d) subcutaneously during the gestational days 9-20 and part of the offspring was given chronic stress at postnatal weeks 10-12. Behavioral results showed that the adult PDE female offspring was susceptible to depression, accompanied by increased hippocampal miR-134-5p expression and decreased sex-determining region Y-box 2 (SOX2) expression, as well as disorders of neural progenitor cells proliferation and hippocampal neurogenesis. The PDE female fetal rats presented consistent changes with the adult offspring, accompanied by the upregulation of glucocorticoid receptor (GR) expression and decreased sirtuin 1 (SIRT1) expression. We further found that the H3K9ac level of the miR-134-5p promoter was significantly increased in the PDE fetal hippocampus, as well as in adult offspring before and after chronic stress. In vitro, the changes of GR/SIRT1/miR-134-5p/SOX2 signal by dexamethasone were consistent with in vivo experiments, which could be reversed by GR receptor antagonist, SIRT1 agonist, and miR-134-5p inhibitor. This study confirmed that PDE led to an increased expression level as well as H3K9ac level of miR-134-5p by activating the GR/SIRT1 pathway in the fetal hippocampus and then inhibited the SOX2 expression. The programming effect mediated by the abnormal epigenetic modification could last from intrauterine to adulthood, which constitutes the intrauterine programming mechanism leading to hippocampal neurogenesis disorders and depression susceptibility in female offspring. Intrauterine programming mechanism for the increased depressive susceptibility in adult female offspring by prenatal dexamethasone exposure (PDE). GR, glucocorticoid receptor; SIRT1, sirtuin 1; SOX2, sex-determining region Y-box 2; NPCs, neuroprogenitor cells; H3K9ac, histone 3 lysine 9 acetylation; GRE, glucocorticoid response element.

Evidence of hypoglycemic anhedonia and modulation by bupropion in rats

BACKGROUND

Disorders characterized by dysfunction of glucose metabolism are often comorbid with depression. The current study investigated whether a hypoglycemic state caused by 2-deoxy-d-glucose (2-DG) can result in anhedonic behaviors responsive to stimulation of monoamine activity.

METHODS

In experiment 1, male Sprague-Dawley rats were tested for maintenance of intra-oral self-administration (IOSA) of a sweet solution after pre-treatment with 300 or 500 mg/kg 2-DG, a blocker of glucose metabolism. Experiment 2 determined whether exposure to an environment previously paired with the effects of 2-DG (0, 200 or 300 mg/kg) can influence IOSA, and whether 2-DG can modify taste reactivity to same sweet solution. Finally, experiment 3 examined whether 0 or 30 mg/kg bupropion, a monoamine-reuptake blocker, would attenuate the effect of 300 mg/kg 2-DG on IOSA and taste reactivity.

RESULTS

It was found that 2-DG produced a sustained decrease in IOSA when animals were tested drug-free. This decrease in IOSA did not appear linked to place conditioning or to alterations in taste reactivity, and it was partially normalized by pre-treatment with bupropion.

CONCLUSIONS

Taken together, these results in rats suggest that rapid hypoglycemia can induce an anhedonic state characterized by impaired consummatory responses to nutritional incentive stimuli and that can be alleviated by the antidepressant bupropion.

Transient Dose-dependent Effects of Ketamine on Neural Oscillatory Activity in Wistar-Kyoto Rats

Ketamine is a promising therapeutic for treatment-resistant depression (TRD) but is associated with an array of short-term psychomimetic side-effects. These disparate drug effects may be elicited through the modulation of neural circuit activity. The purpose of this study was to therefore delineate dose- and time-dependent changes in ketamine-induced neural oscillatory patterns in regions of the brain implicated in depression. Wistar-Kyoto rats were used as a model system to study these aspects of TRD neuropathology whereas Wistar rats were used as a control strain. Animals received a low (10 mg/kg) or high (30 mg/kg) dose of ketamine and temporal changes in neural oscillatory activity recorded from the prefrontal cortex (PFC), cingulate cortex (Cg), and nucleus accumbens (NAc) for ninety minutes. Effects of each dose of ketamine on immobility in the forced swim test were also evaluated. High dose ketamine induced a transient increase in theta power in the PFC and Cg, as well as a dose-dependent increase in gamma power in these regions 10-min, but not 90-min, post-administration. In contrast, only low dose ketamine normalized innate deficits in fast gamma coherence between the NAc-Cg and PFC-Cg, an effect that persisted at 90-min post-injection. These low dose ketamine-induced oscillatory alterations were accompanied by a reduction in immobility time in the forced swim test. These results show that ketamine induces time-dependent effects on neural oscillations at specific frequencies. These drug-induced changes may differentially contribute to the psychomimetic and therapeutic effects of the drug.

Glycogen synthase kinase-3: The missing link to aberrant circuit function in disorders of cognitive dysfunction?

Elevated GSK-3 activity has been implicated in cognitive dysfunction associated with various disorders including Alzheimer's disease, schizophrenia, type 2 diabetes, traumatic brain injury, major depressive disorder and bipolar disorder. Further, aberrant neural oscillatory activity in, and between, cortical regions and the hippocampus is consistently present within these same cognitive disorders. In this review, we will put forth the idea that increased GSK-3 activity serves as a pathological convergence point across cognitive disorders, inducing similar consequent impacts on downstream signaling mechanisms implicated in the maintenance of processes critical to brain systems communication and normal cognitive functioning. In this regard we suggest that increased activation of GSK-3 and neuronal oscillatory dysfunction are early pathological changes that may be functionally linked. Mechanistic commonalities between these disorders of cognitive dysfunction will be discussed and potential downstream targets of GSK-3 that may contribute to neuronal oscillatory dysfunction identified.