Gender differences in depression and response to antidepressant treatment

An overview of the differences in the pharmacological management of post-traumatic stress disorder between women and men

INTRODUCTION

Post-traumatic stress disorder (PTSD) is a disabling psychiatric condition with a worldwide prevalence between 6% and 9%, and more common in the female than in the male sex. The aim of this paper is to review and comment on the different factors that might explain the discrepancies in the pharmacological management of women and men.

AREAS COVERED

The available literature shows that there exists a vulnerability of women to develop PTSD that may depend on neurobiological as well as environmental/cultural factors. These variables might influence the clinical picture, the outcome and the response to specific treatments, given their consequences on the pharmacokinetics of commonly prescribed drugs. Women suffering from PTSD are more prone to consult and receive more prescriptions of psychotropic drugs than men. However, it is evident that the particular stages of a women's life such as pregnancy or breastfeeding might require a specific evaluation and care.

EXPERT OPINION

It is necessary to explore the pharmacokinetics of compounds highlighting sex-related differences, and their safety during pregnancy and lactation. Taking care of differences between women and men should represent a main focus of research, while being a primary target towards a really tailored pharmacological treatment of PTSD.

The impact of menopause on antidepressant response: an explorative analysis from a real-world study

This study endeavors to deepen our understanding of the subject matter by exploring, within a real-world sample, the impact of menopausal status on the antidepressant treatments response. The whole sample included a total of 447 patients, 156 male and 291 female, 110 pre-menopause and 181 post-menopause. In our sample post-menopause women showed a worse response to antidepressants than pre-menopause women (p = 0.006), and this difference seems to be unrelated to age or brain aging.

Nrf2 activation rescues stress-induced depression-like behaviour and inflammatory responses in male but not female rats

BACKGROUND

Major depressive disorder (MDD) is a recurring affective disorder that is two times more prevalent in females than males. Evidence supports immune system dysfunction as a major contributing factor to MDD, notably in a sexually dimorphic manner. Nuclear factor erythroid 2-related factor 2 (Nrf2), a regulator of antioxidant signalling during inflammation, is dysregulated in many chronic inflammatory disorders; however, its role in depression and the associated sex differences have yet to be explored. Here, we investigated the sex-specific antidepressant and immunomodulatory effects of the potent Nrf2 activator dimethyl fumarate (DMF), as well as the associated gene expression profiles.

METHODS

Male and female rats were treated with vehicle or DMF (25 mg/kg) whilst subjected to 8 weeks of chronic unpredictable stress. The effect of DMF treatment on stress-induced depression- and anxiety-like behaviours, as well as deficits in recognition and spatial learning and memory were then assessed. Sex differences in hippocampal (HIP) microglial activation and gene expression response were also evaluated.

RESULTS

DMF treatment during stress exposure had antidepressant effects in male but not female rats, with no anxiolytic effects in either sex. Recognition learning and memory and spatial learning and memory were impaired in chronically stressed males and females, respectively, and DMF treatment rescued these deficits. DMF treatment also prevented stress-induced HIP microglial activation in males. Conversely, females displayed no HIP microglial activation associated with stress exposure. Last, chronic stress elicited sex-specific alterations in HIP gene expression, many of which were normalized in animals treated with DMF. Of note, most of the differentially expressed genes in males normalized by DMF were related to antioxidant, inflammatory or immune responses.

CONCLUSIONS

Collectively, these findings support a greater role of immune processes in males than females in a rodent model of depression. This suggests that pharmacotherapies that target Nrf2 have the potential to be an effective sex-specific treatment for depression.

The effect of prenatal stress on offspring depression susceptibility in relation to the gut microbiome and metabolome

Prenatal stress (PS) increases offspring susceptibility to depression, but the underlying mechanism remains unclear. Our previous results showed that PS can affect depression-like behavior in offspring through neurotransmitters and neuroinflammatory substances in the hippocampus and frontal cortex. In recent years there has been increasing evidence for a role of the gut microbiome in depression. The brain-gut axis theory suggests there is a need to further explore the mechanism involving the gut microbiome in the susceptibility of offspring to depression caused by PS. In the present study we used a stress model relevant to depression in which pregnant female rats undergo prenatal restraint stress and the offspring show susceptibility to depression. High-resolution gene sequencing for 16S ribosomal RNA markers and non-targeted metabolomic analysis were used to evaluate the fecal microbiome and the availability of metabolites, respectively. PS was found to induce depressive-like behavior in susceptible offspring (PS-S), as detected by the sucrose preference and forced swimming tests, as well as altering Alpha and Beta diversity. The different microbiota between the PS-S and control groups were mainly involved in membrane transport, carbohydrate metabolism, amino acid metabolism, and replication and repair pathways. In total, 237 and 136 important differential metabolites with significant influence on modeling analysis were obtained under positive and negative modes, respectively. The main canonical pathways found to be altered were glycerophospholipid metabolism and glycerolipid metabolism. These results suggest that gut microbiota might contribute to the onset of PS-induced depression-like behavior by affecting the glycerophospholipid and glycerolipid metabolic pathways.

Gender Differences in the Psychopathology of Mixed Depression in Adolescents with a Major Depressive Episode

BACKGROUND

Gender differences have been reported in the severity and psychopathological features of major depressive disorders among adults but are poorly reported in adolescent samples.

OBJECTIVE

This study aimed to examine gender differences in the psychopathology of mixed depression among adolescents.

METHODS

We analyzed 341 outpatients with the current major depressive episode (MDE) retrospectively to identify patients with DSM-5 MDE with mixed features. We compared examiner-rated depressive and (hypo)manic symptoms and self- and parent-reported symptoms between sexes.

RESULTS

We identified 76 patients with an MDE with mixed features (67.1% females, 32.9% with bipolar disorder). Depression severity was significantly greater in females versus males (CDRS-R total score 56.2 vs. 48.2, p = 0.014). Depressive symptoms were significantly and independently found to be more severe among females in a logistic regression model, including excessive fatigue (OR 1.68; p = 0.025), low self-esteem (OR 1.67; p = 0.04), excessive weeping (OR 1.62; p = 0.021), and CBCL AAA index (OR 1.04; p = 0.015). None of the depressive symptoms scored greater in males. Males had higher levels of motor activity (2.12 vs. 1.69; p = 0.048) and pressured speech (1.80 vs. 1.24; p = 0.004). Self-rated anxiety (69.3 vs. 56.8, p = 0.047) and CBCL AAA index (207 vs. 189; p = 0.007) were higher in females.

CONCLUSION

Adolescent depression with mixed features is more severe in women, with a higher expression of core affective symptoms and excessive fatigue. While in males, slightly higher levels of psychomotor activation are reported, in females, emotional dysregulation and excessive weeping may subtend a difference in a broader spectrum of mixed features.

Risk Assessment of Depression amongst Women during Menopause before and during the COVID-19 Pandemic

During menopause, the risk of depression is 2-5 times greater than pre- or post-menopause. To assess the risk of depression amongst menopausal women in 2006, compared with 2021 (i.e., during the COVID-19 pandemic), we recruited female volunteers at least 40 years old to complete the menopause rating scale (MRS), the Blatt-Kupperman menopausal index (BKMI), and the Beck depression inventory. Compared with 2006, in 2021, the number of participants who experienced mild, moderate, and severe menopausal symptoms rose by 8%, 1.9%, and 3.2%, respectively. Moreover, the frequency of using hormone replacement therapy rose by 5.1%, feelings of mistrust by 16%, feelings of guilt by 11%, disposition to cry by 25%, mood swings by 12%, and suicidal ideation by 9%, whilst the average body weight and body mass index fell by 5.1 kg and 2.3%, respectively. In 2006 and 2021, 46.3% and 59.3% of participants experienced moderate depression, whereas 3.0% and 5.2% experienced severe depression. The number of participants who denied needing support during menopause decreased by 14.6%, whereas the demand for support from husbands and friends increased by 18.3% and 9.8%, respectively. In 2021, the number of participants who experienced menopausal symptoms, a loss of trust, self-blame, a tendency to cry, mood swings, suicidal ideation, and anxiety also increased compared with 2006, whilst the number of participants without depressive symptoms decreased, but with suspected mild or severe depression increased. Last, menopausal complaints caused an increase in depressive mood in 2021, as evaluated using the BKMI and MRS.

Risk of Depression during Menopause in Women from Poland, Belarus, Belgium, and Greece

Introduction: Menopause is a physiological period in a woman’s life, but it is often accompanied by symptoms that affect mental well-being and general health, including a tendency for depression. Aim of the study: To evaluate the predisposition to the symptoms of depression in women from Poland, Belarus, Belgium, and Greece. Material and methods: the method of diagnostic survey was used, and the research tools were: The Menopause Rating Scale, the Kupperman Index, Beck Depression Inventory, and a self-made survey questionnaire. Results: Hormone replacement therapy (HRT) was used by 15.8% of Polish, 19% of Belgian, 14.3% of Belarusian, and 15.2% of Greek women patients. The mean value of the Kupperman Index (range 0–63) in Poland was 14.8 ± 8.6, in Belgium—15.5 ± 6.6, Belarus—14.0 ± 9.4, and Greece—10.8 ± 6.5, while the total measure of Menopause Rating Scale (MRS) (range 0–44) was 12.2 ± 7.6 in Poland, 13.8 ± 6.5 in Belgium, 10.8 ± 8.0 in Belarus and 12.9 ± 7.4 in Greece. The severity of mental distress followed a similar pattern across all countries (slightly stronger than mild). The results for somatic complaints were similar, whereas the level of sexual issues varied, with the highest in Belgium and the lowest in Belarus. The mildest symptoms of menopause were experienced by Belarusian women and the most severe by Belgian women. The severity of depression, according to the Beck Depression Inventory (range 0–63), was as follows: Poland 10.5 ± 7.9; Belgium—11.1 ± 5.7; Belarus—13.7 ± 5.7; Greece—11.8 ± 6.6. Conclusions: The differences between the development of perimenopausal-related symptoms across countries were statistically significant. The incidence and severity of depression showed statistically significant differences between the countries studied—the highest was in Belarus and the lowest in Poland. Depression levels were not differentiated by subjects’ age or the use of hormone therapy but by subjects’ education. In Poland and Belarus, increased menopausal pain measured by the Kupperman Index altered levels of depression; in Belgium, there were no such correlations, and in Greece, the correlation was statistically significant, but its strength was negligible. A clearer correlation of the effects of development in menopausal symptoms on the level of depression was shown when measured with the MRS scale—in Greece and Belgium, the correlation was relatively weak, but in Poland and Belarus, it was relatively high.

Quercetin reverses chronic unpredictable mild stress-induced depression-like behavior in vivo by involving nuclear factor-E2-related factor 2

Quercetin is a flavonoid compound rich in many natural plants with a wide range of pharmacological effects and nutritional value. Although previous studies have initially shown the antidepressant effect of quercetin in some models. However, the exact mechanism of the antidepressant effect of quercetin on the depression model induced by chronic unpredictable mild stress (CUMS) is still unclear or has not been clearly elucidated. The present study aimed to investigate the antidepressant effect of quercetin in vivo on a CUMS-induced depression model that is closest to human depression, and to explore its mechanism of action around nuclear factor-E2-related factor 2 (Nrf2) related signaling pathways, for the first time. Our results demonstrated that CUMS for 21 consecutive days caused significant decreases in the sucrose preference, and the horizontal score and vertical score in the open field test of mice respectively by 22.6%, 34.4%, and 66.6% (all P < 0.01), and a significant increase in the immobility time during the forced swimming test by 110.5% (P < 0.01), but fortunately, after chronic oral administration of high dose quercetin at 40 mg/kg, the abnormalities of the above indicators were significantly reversed by 26.2%, 40.1%, 152.7%, 43.5% (all P < 0.01). Further western blot analysis showed that CUMS caused the phosphorylation or expression levels of phosphoinositide 3-kinase (PI3K), protein kinase B (Akt), Nrf2 and heme oxygenase-1 (HO-1) proteins in the hippocampus of mice to significantly down-regulate by 60.0%, 72.1%, 90.0% and 50.1% (all P < 0.01), while after chronic oral administration of high dose quercetin at 40 mg/kg, the abnormalities of these proteins were significantly up-regulated by 85.8%, 182.0%, 325.1% and 60.3% (all P < 0.01). In addition, CUMS also caused significant reduction in the levels of antioxidants including superoxide dismutase (SOD) and glutathione-s transferase (GST) in the mice hippocampus by 51.3%, 40.3% (both P < 0.01), while after chronic oral administration of high dose quercetin at 40 mg/kg, the abnormalities of the above indicators were significantly reversed by 69.2% and 49.5% (both P < 0.01), as well as significant elevation in the levels of lipid peroxide malondialdehyde (MDA), inflammation medium nitric oxide (NO) and inducible nitric oxide synthase (iNOS) by 156.4%, 255.4% and 72.7% (all P < 0.01), while after chronic oral administration of high dose quercetin at 40 mg/kg, the abnormalities of the above indicators were significantly reversed by 45.9%, 26.8% and 55.2% (all P < 0.01). The medium dose of quercetin (20 mg/kg) only reversed some of the above indicators, while the low dose of quercetin (10 mg/kg) had no reversal effect on the above indicators. Collectively, the present study confirmed for the first time that quercetin weakened CUMS-induced depression in vivo, and its mechanism was at least partially attributable to the upregulation of hippocampal Nrf2 and the inhibition of iNOS, thereby correcting the central inflammatory response, and the imbalance between oxidation and antioxidant.

Sex Differences in Dopamine Receptors and Relevance to Neuropsychiatric Disorders

Dopamine is an important neurotransmitter that plays a key role in neuropsychiatric illness. Sex differences in dopaminergic signaling have been acknowledged for decades and have been linked to sex-specific heterogeneity in both dopamine-related behaviours as well as in various neuropsychiatric disorders. However, the overall number of studies that have evaluated sex differences in dopamine signaling, both in health and in these disorders, is low. This review will bring together what is known regarding sex differences in innate dopamine receptor expression and function, as well as highlight the known sex-specific roles of dopamine in addiction, depression, anxiety, schizophrenia, and attention deficit hyperactivity disorder. Due to differences in prognosis, diagnosis, and symptomatology between male and female subjects in disorders that involve dopamine signaling, or in responses that utilize pharmacological interventions that target dopamine receptors, understanding the fundamental sex differences in dopamine receptors is of vital importance for the personalization of therapeutic treatment strategies.

A synaptic locus for TrkB signaling underlying ketamine rapid antidepressant action

Ketamine produces rapid antidepressant action in patients with major depression or treatment-resistant depression. Studies have identified brain-derived neurotrophic factor (BDNF) and its receptor, tropomyosin receptor kinase B (TrkB), as necessary for the antidepressant effects and underlying ketamine-induced synaptic potentiation in the hippocampus. Here, we delete BDNF or TrkB in presynaptic CA3 or postsynaptic CA1 regions of the Schaffer collateral pathway to investigate the rapid antidepressant action of ketamine. The deletion of Bdnf in CA3 or CA1 blocks the ketamine-induced synaptic potentiation. In contrast, ablation of TrkB only in postsynaptic CA1 eliminates the ketamine-induced synaptic potentiation. We confirm BDNF-TrkB signaling in CA1 is required for ketamine's rapid behavioral action. Moreover, ketamine application elicits dynamin1-dependent TrkB activation and downstream signaling to trigger rapid synaptic effects. Taken together, these data demonstrate a requirement for BDNF-TrkB signaling in CA1 neurons in ketamine-induced synaptic potentiation and identify a specific synaptic locus in eliciting ketamine's rapid antidepressant effects.

A Systematic Review of the Efficacy of Repetitive Transcranial Magnetic Stimulation Treatment for Women with Postpartum Depression

Transcranial Magnetic Stimulation (TMS) has a strong evidence base for the treatment of major depressive disorder (MDD), however, there is minimal research investigating the treatment of depression within the postpartum period. This systematic review aims to systematically examine the efficacy and safety of TMS when treating postpartum depression (PPD). Databases Ovid Medline, PsycINFO, EMBASE and PubMed were searched from inception to May 2021, to identify peer-reviewed papers assessing the administration of TMS for PPD treatment. Data were systematically extracted and evaluated regarding clinical psychiatric outcomes, social-relational outcomes, neuropsychological testing, and side effects. This systematic review included one randomised controlled trial, two open-label studies, two conference papers, and two case studies, providing data on 60 participants. TMS appears well tolerated, with no reported major adverse side effects. While the studies reported a general reduction in PPD symptoms, the poor quality of the evidence available indicates that TMS for PPD is unable to be currently recommended. However, the substantial evidence for TMS in the treatment of MDD and the differential response to antidepressant medication in PPD indicates that further research into TMS for PPD is warranted.

S-Palmitoylation of Synaptic Proteins as a Novel Mechanism Underlying Sex-Dependent Differences in Neuronal Plasticity

Although sex differences in the brain are prevalent, the knowledge about mechanisms underlying sex-related effects on normal and pathological brain functioning is rather poor. It is known that female and male brains differ in size and connectivity. Moreover, those differences are related to neuronal morphology, synaptic plasticity, and molecular signaling pathways. Among different processes assuring proper synapse functions are posttranslational modifications, and among them, S-palmitoylation (S-PALM) emerges as a crucial mechanism regulating synaptic integrity. Protein S-PALM is governed by a family of palmitoyl acyltransferases, also known as DHHC proteins. Here we focused on the sex-related functional importance of DHHC7 acyltransferase because of its S-PALM action over different synaptic proteins as well as sex steroid receptors. Using the mass spectrometry-based PANIMoni method, we identified sex-dependent differences in the S-PALM of synaptic proteins potentially involved in the regulation of membrane excitability and synaptic transmission as well as in the signaling of proteins involved in the structural plasticity of dendritic spines. To determine a mechanistic source for obtained sex-dependent changes in protein S-PALM, we analyzed synaptoneurosomes isolated from DHHC7-/- (DHHC7KO) female and male mice. Our data showed sex-dependent action of DHHC7 acyltransferase. Furthermore, we revealed that different S-PALM proteins control the same biological processes in male and female synapses.

Stress-induced alterations of mesocortical and mesolimbic dopaminergic pathways

Our ability to develop the cognitive strategies required to deal with daily-life stress is regulated by region-specific neuronal networks. Experimental evidence suggests that prolonged stress in mice induces depressive-like behaviors via morphological, functional and molecular changes affecting the mesolimbic and mesocortical dopaminergic pathways. Yet, the molecular interactions underlying these changes are still poorly understood, and whether they affect males and females similarly is unknown. Here, we used chronic social defeat stress (CSDS) to induce depressive-like behaviors in male and female mice. Density of the mesolimbic and mesocortical projections was assessed via immuno-histochemistry combined with Sholl analysis along with the staining of activity-dependent markers pERK and c-fos in the ventral tegmental area (VTA), nucleus accumbens (NAc) and medial prefrontal cortex (mPFC). Our results show that social stress decreases the density of TH⁺ dopaminergic axonal projections in the deep layers of the mPFC in susceptible but not resilient male and female mice. Consistently, our analyses suggest that pERK expression is decreased in the mPFC but increased in the NAc following CSDS in males and females, with no change in c-fos expression in both sexes. Overall, our findings indicate that social defeat stress impacts the mesolimbic and mesocortical pathways by altering the molecular interactions regulating somatic and axonal plasticity in males and females.

Elevated Brain Fatty Acid Amide Hydrolase Induces Depressive-Like Phenotypes in Rodent Models: A Review

Altered activity of fatty acid amide hydrolase (FAAH), an enzyme of the endocannabinoid system, has been implicated in several neuropsychiatric disorders, including major depressive disorder (MDD). It is speculated that increased brain FAAH expression is correlated with increased depressive symptoms. The aim of this scoping review was to establish the role of FAAH expression in animal models of depression to determine the translational potential of targeting FAAH in clinical studies. A literature search employing multiple databases was performed; all original articles that assessed FAAH expression in animal models of depression were considered. Of the 216 articles that were screened for eligibility, 24 articles met inclusion criteria and were included in this review. Three key findings emerged: (1) FAAH expression is significantly increased in depressive-like phenotypes; (2) genetic knockout or pharmacological inhibition of FAAH effectively reduces depressive-like behavior, with a dose-dependent effect; and (3) differences in FAAH expression in depressive-like phenotypes were largely localized to animal prefrontal cortex, hippocampus and striatum. We conclude, based on the animal literature, that a positive relationship can be established between brain FAAH level and expression of depressive symptoms. In summary, we suggest that FAAH is a tractable target for developing novel pharmacotherapies for MDD.

Exploring the Spatial Distribution Characteristics of Emotions of Weibo Users in Wuhan Waterfront Based on Gender Differences Using Social Media Texts

The benefits of the natural environment in urban space have been explored in numerous studies. However, only a few statistics and studies have been conducted on the correlation between emotion and urban waterfront space, especially considering gender differences. Taking Wuhan city as an example, this study puts forward a new approach and perspective. Text emotion analysis is combined with the spatial analysis technique based on big data of social media. Based on the emotions of the public of different genders in urban space, suggestions are provided for urban planning and development from the perspective of POI (Point of Interest). The main steps are: (1) Analyzing the emotional score of Weibo texts published by citizens in the waterfront area of 21 lakes in Wuhan City; (2) exploring the public emotion characteristics of different genders in the urban waterfront; (3) classifying the waterfront according to the emotional response (score) of the public of different genders; (4) exploring the relationship between different POI types and waterfront types and proposing planning suggestions. The results of this study provide evidence for gender differences and spatial distribution of public emotions in the Wuhan waterfront area. It can help decision-makers to judge the prior protection and development direction of waterfront space, thus demonstrating the feasibility of this approach.

Racial and Ethnic Disparities in Treatment and Treatment Type for Depression in a National Sample of Medicaid Recipients

OBJECTIVE

The purpose of this secondary data analysis was to describe racial-ethnic disparities in receipt of depression treatment and treatment modality among adult Medicaid beneficiaries with depression from a nationally representative sample-28 states and the District of Columbia-of Medicaid beneficiaries (N=599,421).

METHODS

Medicaid claims data were extracted from the full 2008-2009 Medicaid Analytic Extract file. The primary outcome was type of depression treatment: medication only, therapy only, medication and therapy, and no treatment. The secondary outcome was treatment for depression (yes-no). Crude and adjusted odds ratios (AORs) were generated for univariate and multivariate models, respectively, and 95% confidence intervals of odds ratios and p values were calculated.

RESULTS

There were 599,421 individuals in the sample. Rates of depression treatment were lower for African Americans and Hispanics, compared with Caucasians. Percentages receiving no treatment were 19.9% of African Americans, 15.2% of Hispanics, and 11.9% of Caucasians. After full adjustment, African Americans were about half as likely as Caucasians to receive treatment (AOR=0.52), Hispanics were about a third as likely (AOR=0.71), and those from other racial-ethnic groups were about a fifth as likely (AOR=0.84). Caucasians were more likely than any other group to receive medication only.

CONCLUSIONS

This study contributes to evidence about the intersection of social factors and health outcomes and discusses health care engagement, stigma, and policy drivers of racial-ethnic disparities. The study is the first to identify disparities in rates and types of depression treatment among racial-ethnic subgroups of Medicaid beneficiaries in a nationally representative sample.

Fluoxetine effects on behavior and adult hippocampal neurogenesis in female C57BL/6J mice across the estrous cycle

RATIONALE

Some mood disorders, such as major depressive disorder, are more prevalent in women than in men. However, historically preclinical studies in rodents have a lower inclusion rate of females than males, possibly due to the fact that behavior can be affected by the estrous cycle. Several studies have demonstrated that chronic antidepressant treatment can decrease anxiety-associated behaviors and increase adult hippocampal neurogenesis in male rodents.

OBJECTIVE

Very few studies have looked at the effects of antidepressants on behavior and neurogenesis across the estrous cycle in naturally cycling female rodents.

METHODS

Here, we analyze the effects of chronic treatment with the selective serotonin reuptake inhibitor (SSRI) fluoxetine (Prozac) on behavior and adult hippocampal neurogenesis in naturally cycling C57BL/6J females across all four phases of the estrous cycle.

RESULTS

In naturally cycling C57BL/6J females, fluoxetine decreases negative valence behaviors associated with anxiety in the elevated plus maze and novelty-suppressed feeding task, reduces immobility time in forced swim test, and increases adult hippocampal neurogenesis. Interestingly, the effects of fluoxetine on several negative valence behavior and adult hippocampal neurogenesis measures were mainly found within the estrus and diestrus phases of the estrous cycle.

CONCLUSIONS

Taken together, these data are the first to illustrate the effects of fluoxetine on behavior and adult hippocampal neurogenesis across all four phases of the murine estrous cycle.

Depression, changes in peripheral blood cell count, and changes in selected biochemical parameters related to lead concentration in whole blood (Pb-B) of women in the menopausal period

THE AIM

The aim of this study was to assess the severity of depression, vasomotor symptoms, changes in peripheral blood cell count, and selected biochemical parameters in relation to the concentration of lead in whole blood of women in the perimenopausal period.

METHODS

The study sample consisted of 233 women from the general population of the West Pomeranian Province (Poland) in age between 44-65 years. The intensity of menopausal symptoms was examined using the Blatt-Kupperman Index, and the severity of depression using the Beck Depression Inventory. The following biochemical data were evaluated: concentrations of glucose, triglycerides, HDL, C-reactive protein, glycated haemoglobin, cortisol, insulin, blood cell count, and lead concentration in whole blood (Pb-B).

RESULTS

A whole blood Pb concentration below 5 μg/dl was found in 55 subjects (23.61 %), in 142 women (60.94 %) it ranged from 5 to 10 μg/dl, while in 36 women (15.45 %) was higher than 10 μg/dl. There was a strong positive correlation between Pb concentration in the blood of the examined women and the severity of depressive symptoms (Rs=+0.60, p = 0.001). The lowest mean values for total leukocytes (5.07 ± 1.22 thousand/μl) and neutrophils (2.76 ± 0.86 thousand/μl) were found in women with Pb concentration above 10 μg/dl (p < 0.05). There was a significant negative correlation between the number of total leukocytes (r=-0.45, p = 0.002) and neutrophils (r=-0.50, p = 0.001) and blood Pb concentration. Analysis showed statistically significant differences in glucose concentration (p < 0.05) between groups. Blood glucose was higher in women with Pb-B <5 and between 5-10 μg/dl than in women with Pb-B >10 μg/dl.

CONCLUSION

Exposure to Pb may be a factor playing a significant role in the development of depressive symptoms in menopausal women. It may also be associated with glucose metabolism disorders and immunosuppression in women during this period of life.

Antidepressant-like effects of pharmacological inhibition of FAAH activity in socially isolated female rats

Pharmacological inhibition of the enzyme fatty acid amide hydrolase (FAAH), which terminates signaling of the endocannabinoid N-arachidonoylethanolamine (or anandamide, AEA), exerts favourable effects in rodent models of stress-related depression. Yet although depression seems to be more common among women than men and in spite of some evidence of sex differences in treatment efficacy, preclinical development of FAAH inhibitors for the pharmacotherapy of stress-related depression has been predominantly conducted in male animals. Here, adult female rats were exposed to six weeks of social isolation and, starting from the second week, treated with the FAAH inhibitor URB694 (0.3 mg/kg/day, i.p.) or vehicle. Compared to pair-housed females, socially isolated female rats treated with vehicle developed behavioral (mild anhedonia, passive stress coping) and physiological (reduced body weight gain, elevated plasma corticosterone levels) alterations. Moreover, prolonged social isolation provoked a reduction in brain-derived neurotrophic factor (BDNF) and AEA levels within the hippocampus. Together, these changes are indicative of an increased risk of developing a depressive-like state. Conversely, pharmacological inhibition of FAAH activity with URB694 restored both AEA and BDNF levels within the hippocampus of socially isolated rats and prevented the development of behavioral and physiological alterations. These results suggest a potential interplay between AEA-mediated signaling and hippocampal BDNF in the pathogenesis of depression-relevant behaviors and physiological alterations and antidepressant action of FAAH inhibition in socially isolated female rats.

Antidepressant effects of ketamine on depression-related phenotypes and dopamine dysfunction in rodent models of stress

Depression, the most prevalent psychiatric disorder, is characterized by increased negative affect (i.e. depressed mood) and reduced positive affect (i.e. anhedonia). Stress is a risk factor for depression in humans, and animal models of chronic stress are typically used to study neurobehavioral alterations relevant to depression. Common behavioral outcomes in rodent models of chronic stress include anhedonia, social dysfunction and behavioral despair. For example, chronically stressed rodents exhibit reduced reward preference, as measured by a loss of preference for sucrose solutions and time spent interacting with a novel conspecific, while also exhibiting less time struggling against inescapable stressors (e.g. forced swim, tail suspension). In both humans and rodents, anhedonia is associated with dysfunction of the dopamine (DA) system. Unlike traditional antidepressants, which are limited by inadequate efficacy and delayed therapeutic response, acute ketamine administration rapidly alleviates depressive symptoms in humans and reverses stress-induced changes in animal models. These effects are partially mediated via actions on the DA system. This review summarizes the clinical effects of ketamine, the neurobiological underpinnings of depression with a focus on DA dysfunction, as well as antidepressant effects of ketamine on depression-related endophenotypes (i.e. anhedonia, despair) and ventral tegmental area (VTA) activity in rodent models of repeated stress. Moreover, we discuss evidence regarding sex differences in ketamine's antidepressant effects, wherein females appear to be more sensitive to lower dose ketamine, as well as novel findings suggesting that ketamine has prophylactic effects with regard to protection against the neurobehavioral impact of future stressors.

Structural plasticity of the hippocampus in response to estrogens in female rodents

It is well established that estrogens affect neuroplasticity in a number of brain regions. In particular, estrogens modulate and mediate spine and synapse formation as well as neurogenesis in the hippocampal formation. In this review, we discuss current research exploring the effects of estrogens on dendritic spine plasticity and neurogenesis with a focus on the modulating factors of sex, age, and pregnancy. Hormone levels, including those of estrogens, fluctuate widely across the lifespan from early life to puberty, through adulthood and into old age, as well as with pregnancy and parturition. Dendritic spine formation and modulation are altered both by rapid (likely non-genomic) and classical (genomic) actions of estrogens and have been suggested to play a role in the effects of estrogens on learning and memory. Neurogenesis in the hippocampus is influenced by age, the estrous cycle, pregnancy, and parity in female rodents. Furthermore, sex differences exist in hippocampal cellular and molecular responses to estrogens and are briefly discussed throughout. Understanding how structural plasticity in the hippocampus is affected by estrogens and how these effects can influence function and be influenced by other factors, such as experience and sex, is critical and can inform future treatments in conditions involving the hippocampus.

Sex differences in response to ketamine as a rapidly acting intervention for treatment resistant depression

BACKGROUND

While ketamine has been increasingly studied for treatment resistant depression (TRD), the impact of sex differences on treatment outcomes has not been well studied. The objective was to ascertain whether there were differences in response to a single administration of ketamine for TRD between men and women, and between pre- and post-menopausal women.

METHODS

A randomized, double-blind, placebo-controlled trial (N = 99; N = 50 male; N = 49 female) was conducted to investigate the efficacy of intravenous ketamine versus active placebo as augmentation of antidepressant therapy for TRD. Patients were assigned to one of five arms; one-time administration of ketamine of varying doses (i.e., 0.1, 0.2, 0.5, and 1.0 mg/kg), and one group receiving active placebo (intravenous midazolam). A priori-planned analyses were conducted to compare responses between women and men, as well pre-vs. postmenopausal women.

RESULTS

Analyses demonstrated no significant differences between women and men in terms of treatment response (F(1,80) = 0.06, p = 0.80). There were no significant differences in the frequency of adverse effects (AEs) reported by those assigned to ketamine treatment groups (p > 0.21 for all AEs reported more than once), although women reported more headaches (12% vs. 6%, p = 0.30) and nausea (10% vs. 6%, p = 0.47). In comparing pre-vs. postmenopausal women, no differences in efficacy were observed (F(1,76) = 0.36, p = 0.55).

CONCLUSIONS

Results do not support differential efficacy or tolerability of ketamine for the treatment of TRD between women and men, nor based on menopause status among women. However, larger trials with these a priori aims are needed to confirm these results.

Effects of chronic unpredictable mild stress induced prenatal stress on neurodevelopment of neonates: Role of GSK-3β

Prenatal stress (PNS) has gained attention with regard to its impact on hippocampal neurogenesis in neonates which serves as a risk factor for postnatal neurodevelopmental deficits. Evidences from animal models have suggested that depression responsive hypothalamic-pituitary-adrenal (HPA) axis and its hormonal response via cortisol, is responsible for critical neurodevelopmental deficits in the offspring which is transduced due to gestational stress. But knowledge in the area of assessing the effects of maternal chronic unpredictable mild stress (CUMS) on neurogenesis and expression of some key signaling molecules in the offsprings are limited. We have used Wistar rats to induce PNS in offsprings by maternal CUMS during pregnancy. Prefrontal cortex (PFC) and hippocampus were assessed for biomarkers of oxidative stress, neurogenesis, neurodevelopmental signaling molecules and DNA damage in the male Wister offsprings. Our investigations resulted in sufficient evidences which prove how maternal psychological stress has widespread effect on the fetal outcomes via major physiological alteration in the antioxidant levels, neurogenesis, signaling molecules and DNA damage. PNS leads to the upregulation of GSK-3β which in turn inhibited mRNA and protein expressions of sonic hedgehog (SHH), β-catenin, Notch and brain derived neurotrophic factor (BDNF). The study explored multifaceted signaling molecules especially, GSK-3β responsible for crosstalks between different neurodevelopmental molecules like SHH, Notch, BDNF and β-catenin affecting neurodevelopment of the offsprings due to PNS.

The psychoneuroimmunology of pregnancy

Pregnancy is associated with a number of significant changes in maternal physiology. Perhaps one of the more notable changes is the significant alteration in immune function that occurs during pregnancy. This change in immune function is necessary to support a successful pregnancy, but also creates a unique period of life during which a female is susceptible to disease and, as we'll speculate here, may also contribute to mental health disorders associated with pregnancy and the postpartum period. Here, we review the known changes in peripheral immune function that occur during pregnancy and the postpartum period, while highlighting the impact of hormones during these times on immune function, brain or neural function, as well as behavior. We also discuss the known and possible impact of pregnancy-induced immune changes on neural function during this time and briefly discuss how these changes might be a risk factor for perinatal anxiety or mood disorders.

Effects of n-3 PUFA enriched and n-3 PUFA deficient diets in naïve and Aβ-treated female rats

Depression is one of the most common psychiatric diseases and the prevalence of depressive symptoms in women is almost twice compared to men, although the reasons of this gender difference are not fully understood yet. Recently, soluble Aβ_1-42 peptide has been receiving great importance in the development of depression, also since depression is highly comorbid with Alzheimer's disease and other neurodegenerative illnesses. Accordingly, we have previously shown that central Aβ injection is able to elicit depressive-like phenotype in male rats. In the present study, we reproduced for the first time the Aβ-induced depressive-like model in female rats, evaluating behavioural and neurochemical outcomes. Moreover, we studied the effect of lifelong exposure to either n-3 PUFA enriched or n-3 PUFA deficient diet, in female rats, both intact and after central Aβ administration. Our results confirmed the Aβ-induced depressive-like profile also in female rats. Moreover, chronic exposure to n-3 PUFA deficient diet led to highly negative alterations in behavioural and neurochemical parameters, while lifelong exposure to n-3 PUFA enriched diet was able to restore the Aβ-induced depressive-like profile in female rats. In conclusion, the Aβ-induced depressive-like profile was reversed by n-3 PUFA supplementation, indicating a possible therapeutic role of n-3 PUFA in the treatment of the burden of depressive disorders.

Neuroplasticity pathways and protein-interaction networks are modulated by vortioxetine in rodents

Background

The identification of biomarkers that predict susceptibility to major depressive disorder and treatment response to antidepressants is a major challenge. Vortioxetine is a novel multimodal antidepressant that possesses pro-cognitive properties and differentiates from other conventional antidepressants on various cognitive and plasticity measures. The aim of the present study was to identify biological systems rather than single biomarkers that may underlie vortioxetine’s treatment effects.

Results

We show that the biological systems regulated by vortioxetine are overlapping between mouse and rat in response to distinct treatment regimens and in different brain regions. Furthermore, analysis of complexes of physically-interacting proteins reveal that biomarkers involved in transcriptional regulation, neurodevelopment, neuroplasticity, and endocytosis are modulated by vortioxetine. A subsequent qPCR study examining the expression of targets in the protein–protein interactome space in response to chronic vortioxetine treatment over a range of doses provides further biological validation that vortioxetine engages neuroplasticity networks. Thus, the same biology is regulated in different species and sexes, different brain regions, and in response to distinct routes of administration and regimens.

Conclusions

A recurring theme, based on the present study as well as previous findings, is that networks related to synaptic plasticity, synaptic transmission, signal transduction, and neurodevelopment are modulated in response to vortioxetine treatment. Regulation of these signaling pathways by vortioxetine may underlie vortioxetine’s cognitive-enhancing properties.

Electronic supplementary material

The online version of this article (doi:10.1186/s12868-017-0376-x) contains supplementary material, which is available to authorized users.

Depression in systemic lupus erythematosus: gender differences in the performance of the Beck Depression Inventory (BDI), Center for Epidemiologic Studies Depression Scale (CES-D), and Hospital Anxiety and Depression Scale (HADS)

The prevalence of depressive symptoms in patients with systemic lupus erythematosus (SLE) varies widely between different cohorts (17-75%), primarily due to factors such as the heterogeneity of the samples and the instruments used to detect depressive symptoms. Most of these instruments are self-administered questionnaires that have different characteristics and approaches to depressive symptoms. This study aimed to evaluate gender differences in the performance of three questionnaires used to assess depressive symptoms in patients with SLE: the Beck Depression Inventory (BDI), Center for Epidemiologic Studies Depression Scale (CES-D), and Hospital Anxiety and Depression Scale (HADS). This study included 54 male and 54 female SLE patients. Depressive symptoms were assessed using BDI (cutoffs 13 and 15), CES-D and HADS. The gold standard method used was the diagnostic criteria of the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders. Regarding the performance of the BDI questionnaire, no significant differences in sensitivity or specificity were found between the genders. The specificity of the CES-D questionnaire was significantly greater for the male group (83% vs. 62.5%, p = 0.0309), and its sensitivity was non-significantly higher for the female group (92.9% for women and 71.4% for men; p = 0.2474). Regarding the performance of the HADS, we found similar sensitivities between the genders (71.4%) but a higher specificity among the men (95.7% in men and 82.5% in women, p = 0.0741). In conclusion, our results suggest the presence of gender differences in the performance of the questionnaires in SLE patients. The BDI had the most similar performances between the male and female groups. In contrast, the CES-D and HADS-D showed considerable variation in performances between men and women with SLE.

Long-Term Sertraline Intake Reverses the Behavioral Changes Induced by Prenatal Stress in Rats in a Sex-Dependent Way

Early life stress is a major factor underlying the vulnerability to respond to stressful events later in life. The present study attempted to evaluate the role of prenatal stress affecting the development of stress-related disorders and their reversion by postnatal exposure to Sertraline (SERT), a front-line medication for medication for posttraumatic stress disorder (PTSD) in humans. To achieve this, adult male and female prenatally stressed (PS) or unstressed (Controls) offspring rats, following oral chronic treatment with SERT (5 mg/kg/day; from 1 month to 4 months old), or not, were studied prior to and after a traumatic event. First, anxiety-like behavior during the prepulse inhibition (PPI) test, a modulation of the startle reflex, was examined in all animals. Subsequently, the animals were subjected to a session of mild inescapable footshocks (IS; 0.35 mA, 5 s) in a shuttle box that was followed by 4 days of situational reminders in the aversive context. Prior to the footshocks no effects of PS or SERT were shown, and no changes in PPI and the habituation to the shuttle box were found. After them, PS led animals to exhibit behavioral alterations. When compared to the Controls, PS animals of both sexes displayed less rearing activity in the aversive environment. PS males responded less to footshock delivery and, in most of the animals, fear extinction was impaired. Moreover, the early postnatal exposure to SERT lessened the behavioral impact of PS in females, while in males it had no effect. Current results extend previous data from our laboratory, showing that PS heightened vulnerability to stress later on, and that SERT acts differently in males and females.

Ovarian hormones modify anxiety behavior and glucocorticoid receptors after chronic social isolation stress

Chronic social isolation could lead to a disruption in the Hypothalamic-Pituitary-Adrenal (HPA) axis, resulting in anxiety and depressive-like behaviors but cycling estrogens could modify these behaviors. The aim of this study was to determine if changes in ovarian hormones during the normal cycle could interact with social isolation to alter anxiety and depressive-like behaviors. In parallel, we examined the expression of glucocorticoid receptor (GR) and synaptic vesicle protein synaptophysin in the hippocampus and hypothalamus of Sprague Dawley normal cycling female rats. We assigned rats to either isolated or paired housing for 8 weeks. To assess anxiety and depressive-like behaviors, we used the open field test and forced swim test, respectively. Female rats were tested at either diestrus, estrus, or proestrus stage of the estrous cycle. After behaviors, rats were perfused and brains collected. Brain sections containing hippocampus and hypothalamus were analyzed using immunohistochemistry for synaptophysin and glucocorticoid receptor (GR) levels. We found an increase in depressive-like behaviors for isolated animals compared to paired housed rats, regardless of the estrous cycle stage. Interestingly, we found a decrease in anxiety behaviors in females in the estrus stage accompanied by a decrease in GR expression in hippocampal DG and CA3. However, no changes in synaptophysin were observed in any of the areas of studied. Our results support the beneficial effects of circulating ovarian hormones in anxiety, possibly by decreasing GR expression.

Gender Differences in Depression

Depression is among the most prevalent and debilitating psychiatric disorders in the world. A striking feature of this disorder is that women are twice as likely to experience depression compared with men. Research indicates that genetic, biological and environmental factors contribute to the gender differences noted in depression. Women are more likely to suffer a greater number of and more severe stressful life events compared with men, although no gender difference has been found to explain the genetic vulnerability. As individuals with depression most frequently present to general practitioners, healthcare providers should consider screening for depression and using rigorous treatment strategies for depressed patients with comorbid medical illnesses.

Depressive Disorders Related to Female Reproductive Transitions

Depression is rapidly becoming a major health concern. Recent estimates rank it as the fourth leading cause of disease burden worldwide, and its incidence is steadily increasing. Women have a risk of experiencing depressive illnesses that is twice that of men. Women with depression also typically experience greater functional impairment. The incidence of depression dramatically increases during the reproductive years, which correspond to ages 25 to 44 years. During this time frame, women may experience several reproductive milestones or transitional events such as menarche, the menstrual cycle, pregnancy, infertility, miscarriage, and perimenopause/menopause. These transitions evoke neuroendocrinologic changes that appear to influence the risk for depressive episodes. Common disorders associated with these hormonal fluctuations include premenstrual dysphoric disorder, postpartum depression, and depression in the perimenopausal transition. Although the specific pathophysiologic association is still unclear, evidence supports that these reproductive transitions influence the risk of depression in women.

Sensitivity of the prefrontal GABAergic system to chronic stress in male and female mice: Relevance for sex differences in stress-related disorders

Stress-induced modifications of the prefrontal cortex (PFC) are believed to contribute to the onset of mood disorders, such as depression and anxiety, which are more prevalent in women. In depression, the PFC is hypoactive; however the origin of this hypoactivity remains unclear. Possibly, stress could impact the prefrontal GABAergic inhibitory system that, as a result, impairs the functioning of downstream limbic structures controlling emotions. Preclinical evidence indicates that the female PFC is more sensitive to the effects of stress. These findings suggest that exposure to stress could lead to sex-specific alterations in prefrontal GABAergic signaling, which contribute to sex-specific abnormal functioning of limbic regions. These limbic changes could promote the onset of depressive and anxiety behaviors in a sex-specific manner, providing a possible mechanism mediating sex differences in the clinical presentation of stress-related mood disorders. We addressed this hypothesis using a mouse model of stress-induced depressive-like behaviors: the unpredictable chronic mild stress (UCMS) paradigm. We observed changes in prefrontal GABAergic signaling after exposure to UCMS most predominantly in females. Increased parvalbumin (PV) expression and decreased prefrontal neuronal activity were correlated in females with severe emotionality deficit following UCMS, and with altered activity of the amygdala. In males, small changes in emotionality following UCMS were associated with minor changes in prefrontal PV expression, and with hypoactivity of the nucleus accumbens. Our data suggest that prefrontal hypoactivity observed in stress-related mood disorders could result from stress-induced increases in PV expression, particularly in females. This increased vulnerability of the female prefrontal PV system to stress could underlie sex differences in the prevalence and symptomatology of stress-related mood disorders.

Differences in pain perception, health-related quality of life, disability, mood, and sleep between Brazilian and Spanish people with chronic non-specific low back pain

Background

Cultural and social factors play an important role in the development and persistence of Low Back Pain (LBP). Nevertheless, there are few studies investigating differences in LBP features between countries.

Objective

To determine differences in pain perception between individuals with LBP living in Brazil and Spain.

Method

Thirty Spanish individuals and 30 age- and sex-comparable Brazilian individuals with LBP were recruited from the Public Health Services of both countries. The Numerical Pain Rating Scale and the pain rating index (PRI), the number of words chosen (NWC), and the present pain index (PPI) extracted from the McGill Pain Questionnaire were used to assess pain. The Oswestry Disability Index, the Short Form-36, Beck Depression Inventory-II, and Pittsburgh Sleep Quality Index were also applied. Differences between countries and the correlation between demographic and clinical variables in each country were assessed with parametric and the nonparametric tests.

Results

A significant Country by Gender interaction was found for the PRI total score (P=0.038), but not for intensity of pain, disability, PPI, or NWC, in which Spanish women exhibited greater pain ratio than Spanish men (P=0.014), and no gender differences were identified in Brazilians. The Spanish group showed a consistent pattern of correlations for clinical data. Within Brazilian patients, fewer correlations were found and all of the coefficients were lower than those in the Spanish group.

Conclusion

The pain perception in patients with LBP is different depending on the country. Within Spanish patients, LBP is considered a more global entity affecting multidimensional contexts.

Overshadowed by the amygdala: the bed nucleus of the stria terminalis emerges as key to psychiatric disorders

The bed nucleus of the stria terminalis (BNST) is a center of integration for limbic information and valence monitoring. The BNST, sometimes referred to as the extended amygdala, is located in the basal forebrain and is a sexually dimorphic structure made up of between 12 and 18 sub-nuclei. These sub-nuclei are rich with distinct neuronal subpopulations of receptors, neurotransmitters, transporters and proteins. The BNST is important in a range of behaviors such as: the stress response, extended duration fear states and social behavior, all crucial determinants of dysfunction in human psychiatric diseases. Most research on stress and psychiatric diseases has focused on the amygdala, which regulates immediate responses to fear. However, the BNST, and not the amygdala, is the center of the psychogenic circuit from the hippocampus to the paraventricular nucleus. This circuit is important in the stimulation of the hypothalamic-pituitary-adrenal axis. Thus, the BNST has been largely overlooked with respect to its possible dysregulation in mood and anxiety disorders, social dysfunction and psychological trauma, all of which have clear gender disparities. In this review, we will look in-depth at the anatomy and projections of the BNST, and provide an overview of the current literature on the relevance of BNST dysregulation in psychiatric diseases.

Postpartum depression: Etiology, treatment and consequences for maternal care

This article is part of a Special Issue "Parental Care". Pregnancy and postpartum are associated with dramatic alterations in steroid and peptide hormones which alter the mothers' hypothalamic pituitary adrenal (HPA) and hypothalamic pituitary gonadal (HPG) axes. Dysregulations in these endocrine axes are related to mood disorders and as such it should not come as a major surprise that pregnancy and the postpartum period can have profound effects on maternal mood. Indeed, pregnancy and postpartum are associated with an increased risk for developing depressive symptoms in women. Postpartum depression affects approximately 10-15% of women and impairs mother-infant interactions that in turn are important for child development. Maternal attachment, sensitivity and parenting style are essential for a healthy maturation of an infant's social, cognitive and behavioral skills and depressed mothers often display less attachment, sensitivity and more harsh or disrupted parenting behaviors, which may contribute to reports of adverse child outcomes in children of depressed mothers. Here we review, in honor of the "father of motherhood", Jay Rosenblatt, the literature on postnatal depression in the mother and its effect on mother-infant interactions. We will cover clinical and pre-clinical findings highlighting putative neurobiological mechanisms underlying postpartum depression and how they relate to maternal behaviors and infant outcome. We also review animal models that investigate the neurobiology of maternal mood and disrupted maternal care. In particular, we discuss the implications of endogenous and exogenous manipulations of glucocorticoids on maternal care and mood. Lastly we discuss interventions during gestation and postpartum that may improve maternal symptoms and behavior and thus may alter developmental outcome of the offspring.

Disturbances in Hypothalamic-Pituitary-Adrenal Axis and Immunological Activity Differentiating between Unipolar and Bipolar Depressive Episodes

INTRODUCTION

Differentiating bipolar depression (BD) from unipolar depression (UD) is difficult in clinical practice and, consequently, accurate recognition of BD can take as long as nine years. Research has therefore focused on the discriminatory capacities of biomarkers, such as markers of the hypothalamic-pituitary-adrenal (HPA) axis or immunological activity. However, no previous study included assessments of both systems, which is problematic as they may influence each other. Therefore, this study aimed to explore whether cortisol indicators and inflammatory markers were a) independently associated with and/or b) showed effect modification in relation to a lifetime (hypo)manic episode in a large sample of depressed patients.

METHODS

Data were derived from the Netherlands Study of Depression and Anxiety and comprised 764 patients with a DSM-IV depressive disorder at baseline, of which 124 (16.2%) had a lifetime (hypo)manic episode at the 2-year assessment, or a more recent episode at the 4-year or 6-year assessment. Baseline cortisol awakening response, evening cortisol and diurnal cortisol slope were considered as cortisol indicators, while baseline C-reactive Protein (CRP), Interleukin-6 (IL-6), and Tumor Necrosis Factor Alpha (TNF-α) were included as inflammatory markers.

RESULTS

In depressed men and women, none of the cortisol indicators and inflammatory markers were (independently) associated with a (hypo)manic episode. However, effect modification was found of diurnal cortisol slope and CRP in relation to a (hypo)manic episode. Further analyses showed that depressed men with high levels of diurnal cortisol slope and CRP had an increased odds (OR=10.99, p=.001) of having a (hypo)manic episode. No significant differences were found in women.

CONCLUSION

Our findings suggest that the combination of high diurnal cortisol slope and high CRP may differentiate between UD and BD. This stresses the importance of considering HPA-axis and immunological activity simultaneously, but more research is needed to unravel their interrelatedness.

Postmenopausal syndrome

Menopause is one of the most significant events in a woman's life and brings in a number of physiological changes that affect the life of a woman permanently. There have been a lot of speculations about the symptoms that appear before, during and after the onset of menopause. These symptoms constitute the postmenopausal syndrome; they are impairing to a great extent to the woman and management of these symptoms has become an important field of research lately. This chapter attempts to understand these symptoms, the underlying pathophysiology and the management options available.

Overweight, obesity and female sexuality in perimenopause: a preliminary report

INTRODUCTION

The research was conducted among patients of the Department of Perinatology and Gynaecology of the Poznań University of Medical Sciences. Its aim was to investigate the influence of overweight and obesity on female sexuality during the perimenopausal period. Preliminary results of the research are presented in the thesis, which was as a matter of fact intended as a preliminary report. The examination of sexual functions of the patients was performed with the use of the Female Sexual Function Index (FSFI) form.

MATERIAL AND METHODS

Sixty-one women during the perimenopausal period filled out the survey, with the average age of these women being 51 years. Forty-two of the examined women had an appropriate body mass index (BMI), i.e. between 18.5 and 25, while for 19 of the women, the BMI was above normal. For statistical analysis and in order to assess the differences between the two above-mentioned groups of patients, the nonparametric Mann-Whitney test was applied. A statistically significant value was assumed at p < 0.05. The results of the conducted research indicated no such difference between the women with differing BMI for the specific domains of the FSFI test.

RESULTS

The results obtained show that research in the area needs to be continued.

CONCLUSIONS

All the hitherto existing scientific studies also seem to indicate that the influence of overweight and obesity on female sexuality during the perimenopause has not yet been unambiguously proven. Beyond any doubt, however, sexual disorders appear in women at this time of life and the factors which determine them can vary greatly. Given the character of the situation, women ought to be supported both by a team of specialists representing different branches of medicine as well as by their relatives. The whole situation also calls for more research of the important subject matter.

Disruption of running activity rhythm following restricted feeding in female mice: Preventive effects of antidepressants

Biological rhythms are critical in the etiology of mood disorders; therefore, effective mood disorder treatments should address rhythm disturbances. Among the variables synchronized with the light-dark cycle, spontaneous activity in rodents is useful for investigating circadian rhythms. However, previous studies have focused only on the increase of wheel-running activity under restricted feeding conditions, while little information is available on circadian rhythm of running activity. In this study, chronometrical analysis was used to assess whether circadian rhythms during wheel-running are altered by restricted feeding and affected by antidepressant drugs. Wheel revolutions were automatically recorded and analyzed using cosinor-rhythmometry in 8-week old ICR albino mice. When feeding was restricted to 1 h per day (21:00-22:00), wheel-running rhythms were reliably disrupted. Female mice exhibited marked alterations in the pattern and extent of wheel-running beginning on day 1. Subchronic treatment with imipramine or paroxetine, as well as tandospirone and (-)-DOI, prevented wheel-running rhythm disruption. Thus, altering the circadian activity rhythms of female mice on a 1-h feeding schedule may be useful for investigating disturbances in biological rhythms.

Sex differences in the chronic mild stress model of depression

A large volume of clinical and experimental evidence documents sex differences in brain anatomy, chemistry, and function, as well as in stress and drug responses. The chronic mild stress model (CMS) is one of the most extensively investigated animal models of chronic stress. However, only a limited number of studies have been conducted in female rodents despite the markedly higher prevalence of major depression among women. Herein, we review CMS studies conducted in rats and mice of both sexes and further discuss intriguing sex-dependent behavioral and neurobiological findings. The PubMed literature search engine was used to find and collect all relevant articles analyzed in this review. Specifically, a multitermed search was performed with 'chronic mild stress', 'chronic unpredictable stress' and 'chronic variable stress' as base terms and 'sex', 'gender', 'females' and 'depression' as secondary terms in various combinations. Male and female rodents appear to be differentially affected by CMS application, depending on the behavioral, physiological, and neurobiological indices that are being measured. Importantly, the CMS paradigm, despite its limitations, has been successfully used to assess a constellation of interdisciplinary research questions in the sex differences field and has served as a 'silver bullet' in assessing the role of sex in the neurobiology of major depression.

Sex differences in the pharmacokinetics of antidepressants: influence of female sex hormones and oral contraceptives

Women are twice as likely to develop depression as men. Moreover, the symptoms they experience also show sex differences: women tend to develop depression at an earlier age and show more severe symptoms than men. Likewise, the response to antidepressant pharmacotherapy appears to have sex differences. These differences can partially be explained by differences in pharmacokinetic properties (i.e., absorption, distribution, metabolism, and excretion) of drugs in males and females. More recent research has shown that sex hormones may influence all these previously named pharmacokinetic processes. As concentrations of sex hormones vary throughout the female lifespan, these hormonal variations can have effects on therapeutic responses to antidepressants as well as the occurrence of adverse events. The purpose of this paper is therefore to review the literature reporting on the effects of female sex hormones on the pharmacokinetics of antidepressants and to discuss and evaluate the implications of changes in levels of sex hormones throughout life for the treatment of depression.

Sex differences in the rapid and the sustained antidepressant-like effects of ketamine in stress-naïve and "depressed" mice exposed to chronic mild stress

During the past decade, one of the most striking discoveries in the treatment of major depression was the clinical finding that a single infusion of a sub-anesthetic dose of the N-methyl-d-aspartate receptor antagonist ketamine produces a rapid (i.e. within a few hours) and long-lasting (i.e. up to two weeks) antidepressant effect in both treatment-resistant depressed patients and in animal models of depression. Notably, converging clinical and preclinical evidence support that responsiveness to antidepressant drugs is sex-differentiated. Strikingly, research regarding the antidepressant-like effects of ketamine has focused almost exclusively on the male sex. Herein we report that female C57BL/6J stress-naïve mice are more sensitive to the rapid and the sustained antidepressant-like effects of ketamine in the forced swim test (FST). In particular, female mice responded to lower doses of ketamine (i.e. 3mg/kg at 30 min and 5mg/kg at 24h post-injection), doses that were not effective in their male counterparts. Moreover, tissue levels of the excitatory amino acids glutamate and aspartate, as well as serotonergic activity, were affected in a sex-dependent manner in the prefrontal cortex and the hippocampus, at the same time-points. Most importantly, a single injection of ketamine (10mg/kg) induced sex-dependent behavioral effects in mice subjected to the chronic mild stress (CMS) model of depression. Intriguingly, female mice were more reactive to the earlier effects of ketamine, as assessed in the open field and the FST (at 30 min and 24h post-treatment, respectively) but the antidepressant potential of the drug proved to be longer lasting in males, as assessed in the splash test and the FST (days 5 and 7 post-treatment, respectively). Taken together, present data revealed that ketamine treatment induces sex-dependent rapid and sustained neurochemical and behavioral antidepressant-like effects in stress-naïve and CMS-exposed C57BL/6J mice.

Influence of sex and stress exposure across the lifespan on endophenotypes of depression: focus on behavior, glucocorticoids, and hippocampus

Sex differences exist in vulnerability, symptoms, and treatment of many neuropsychiatric disorders. In this review, we discuss both preclinical and clinical research that investigates how sex influences depression endophenotypes at the behavioral, neuroendocrine, and neural levels across the lifespan. Chronic exposure to stress is a risk factor for depression and we discuss how stress during the prenatal, postnatal, and adolescent periods differentially affects males and females depending on the method of stress and metric examined. Given that the integrity of the hippocampus is compromised in depression, we specifically focus on sex differences in how hippocampal plasticity is affected by stress and depression across the lifespan. In addition, we examine how female physiology predisposes depression in adulthood, specifically in postpartum and perimenopausal periods. Finally, we discuss the underrepresentation of women in both preclinical and clinical research and how this limits our understanding of sex differences in vulnerability, presentation, and treatment of depression.