The impact of treatment on HPA axis activity in unipolar major depression

Psychoneuroendocrine stress response in female and male youth with major depressive disorder

BACKGROUND

Exposure to psychosocial stress is one of the strongest risk factors for major depressive disorder (MDD) in youth, but underlying neurobiological mechanisms are poorly understood. Previous studies on the neuroendocrine stress response in youth with MDD are scarce, limited to cortisol, and rarely considered sex differences. Due to puberty-associated neuroendocrine transitions increasing the risk for MDD onset in adolescence, this study aimed to investigate sex-specific stress responses of stress and sex hormones as well as of neuropeptides.

METHODS

In 103 pubertal youths with MDD and 72 healthy controls (HCs; 62% females, 12-18 years), psychological stress as well as salivary cortisol, testosterone, and oxytocin reactivity to a standardized psychosocial stress test (Trier Social Stress Test, TSST) were assessed. Effects of group and sex, and their interactions were analyzed using hierarchical linear models, while controlling for potentially confounding factors (such as age and pubertal status).

RESULTS

Females and males with MDD showed a stronger psychological stress response than HCs. In contrast, both female and male youth with MDD showed blunted cortisol, testosterone, and oxytocin stress responses compared to HCs. In addition, baseline testosterone was elevated in MDD compared to HCs.

CONCLUSIONS

Results indicate a discrepant stress reactivity in youth with MDD, with increased psychological, but decreased neuroendocrine responses to psychosocial stress. Blunted neuroendocrine stress responses in youth with MDD were found across different neuroendocrine systems and in both females and males with MDD. These novel findings point to a fundamentally changed stress response in youth with MDD irrespective of sex, which may influence successful stress regulation in the affected adolescents.

Association between fasting blood glucose and psychotic symptoms in Chinese patients with first-episode drug-naïve major depressive disorder

INTRODUCTION

Psychotic depression (PD) is a highly debilitating disorder characterized by hallucinations and/or delusions accompanied by depression. A variety of neurotransmitters, hormones and corresponding receptors in the endocrine system are involved in the onset and progression of depression, and fasting blood glucose (FBG) can be an important indicator for monitoring the stability of the endocrine system. The aim of this study was to investigate the relationship between FBG and PD in a Chinese population with first-episode drug-naïve (FEDN) major depressive disorder (MDD).

METHODS

In this study, 1718 outpatient individuals diagnosed with first-episode drug-naïve major depressive disorder (FEDN MDD) were included. The association between PD and FBG levels was identified through multivariable binary logistic regression analysis. To investigate potential non-linear relationships, a two-piecewise linear regression model was utilized. Additionally, interaction and stratified analyses were performed based on gender, educational background, marital status, presence of comorbid anxiety, and history of suicide attempt.

RESULTS

Multivariate logistic regression analysis showed that FBG was positively associated with the risk of PD in FEDN MDD patients (OR = 1.68, 95% CI: 1.31 to 2.13; P < 0.05). Smoothed plots showed a non-linear relationship between FBG and PD, while the inflection point of FBG was calculated using a two-segmented logistic regression model to be 6.23 mmol/L. On the right side of the inflection point, the probability of PD increased substantially by 278% (OR = 3.78, 95% CI: 1.75 to 8.18, p < 0.001), while no significant association was observed on the left side of the inflection point (OR = 1.06, 95% CI: 0.73 to 1.52, p = 0.772).

CONCLUSIONS

Our investigation revealed a nonlinear relationship between FBG and PD in patients with FEDN MDD, thereby informing more effective intervention strategies for managing psychotic symptoms in individuals with depression.

Depression, Cancer, Inflammation, and Endogenous Opioids: Pathogenic Relationships and Therapeutic Options

Endogenous opioids and their associated receptors form a system that maintains survival by positively reinforcing behaviors that are vital to life. Cancer and cancer treatment side effects capitalize on this system pathogenically, leading to maladaptive biological responses (e.g., inflammation), as well as cognitive and emotional consequences, most notably depression. Psychologists who treat people with cancer frequently find depression to be a primary target for intervention. However, in people with cancer, the etiology of depression is unique and complex. This complexity necessitates that psycho-oncologists have a fundamental working knowledge of the biological substrates that underlie depression/cancer comorbidity. Building on other chapters in this volume pertaining to cancer and endogenous opioids, this chapter focuses on the clinical applications of basic scientific findings.

Prenatal serotonin reuptake inhibitor antidepressant exposure, SLC6A4 genetic variations, and cortisol activity in 6-year-old children of depressed mothers: A cohort study

Prenatal exposure to maternal depression and serotonin reuptake inhibitor (SRI) antidepressants both affect the development of the hypothalamic-pituitary-adrenal (HPA) system, possibly via the neurotransmitter serotonin (5HT). In a community cohort, we investigated the impact of two factors that shape prenatal 5HT signaling (prenatal SRI [pSRI] exposure and child SLC6A4 genotype) on HPA activity at age 6 years. Generalized estimating equation (GEE) models were used to study associations between cortisol reactivity, pSRI exposure, and child SLC6A4 genotype, controlling for maternal depression, child age, and sex (48 pSRI exposed, 74 nonexposed). Salivary cortisol levels were obtained at five time points during a laboratory stress challenge: arrival at the laboratory, following two sequential developmental assessments, and then 20 and 40 min following the onset of a stress-inducing cognitive/social task. Cortisol decreased from arrival across both developmental assessments, and then increased across both time points following the stress challenge in both groups. pSRI-exposed children had lower cortisol levels across all time points. In a separate GEE model, we observed a lower cortisol stress response among children with LG /S alleles compared with children with La/La alleles, and this was particularly evident among children of mothers reporting greater third trimester depressed mood. Our findings suggest that pSRI exposure and a genetic factor associated with modulating 5HT signaling shaped HPA reactivity to a laboratory stress challenge at school age.

Accelerated epigenetic aging and decreased natural killer cells based on DNA methylation in patients with untreated major depressive disorder

Major depressive disorder (MDD) is known to cause significant disability. Genome-wide DNA methylation (DNAm) profiles can be used to estimate biological aging and as epigenetic clocks. However, information on epigenetic clocks reported in MDD patients is inconsistent. Since antidepressants are likely confounders, we evaluated biological aging using various DNAm-based predictors in patients with MDD who had never received depression medication. A publicly available dataset consisting of whole blood samples from untreated MDD patients (n = 40) and controls (n = 40) was used. We analyzed five epigenetic clocks (HorvathAge, HannumAge, SkinBloodAge, PhenoAge, and GrimAge), DNAm-based telomere length (DNAmTL), and DNAm-based age-related plasma proteins (GrimAge components), as well as DNAm-based white blood cell composition. The results indicate that patients with untreated MDD were significantly associated with epigenetic aging acceleration in HannumAge and GrimAge. Furthermore, a decrease in natural killer cells, based on DNAm, was observed in patients with untreated MDD.

DNA Methylation of POMC and NR3C1-1F and Its Implication in Major Depressive Disorder and Electroconvulsive Therapy

INTRODUCTION

Precision medicine in psychiatry is still in its infancy. To establish patient-tailored treatment, adequate indicators predicting treatment response are required. Electroconvulsive therapy (ECT) is considered one of the most effective options for pharmacoresistant major depressive disorder (MDD), yet remission rates were reported to be below 50%.

METHODS

Since epigenetics of the stress response system seem to play a role in MDD, we analyzed the DNA methylation (DNAm) of genes encoding the glucocorticoid receptor (NR3C1) and proopiomelanocortin (POMC) through Sanger Sequencing. For analysis, blood was taken before and after the first and last ECT from MDD patients (n=31), unmedicated depressed controls (UDC; n=19, baseline), and healthy controls (HC; n=20, baseline).

RESULTS

Baseline DNAm in NR3C1 was significantly lower in UDCs compared to both other groups (UDC: 0.014(±0.002), ECT: 0.031(±0.001), HC: 0.024(±0.002); p<0.001), whereas regarding POMC, ECT patients had the highest DNAm levels (ECT: 0.252(±0.013), UDC: 0.156(±0.015), HC: 0.162(±0.014); p<0.001). NR3C1m and POMCm decreased after the first ECT (NR3C1: p<0.001; POMC: p=0.001), and responders were less methylated compared to non-responders in NR3C1(p<0.001).

DISCUSSION

Our findings indicate that both genes might play a role in the chronification of depression and NR3C1 may be relevant for ECT response prediction.

5-HT attenuates chronic stress-induced cognitive impairment in mice through intestinal flora disruption

BACKGROUND

The microbiota-gut-brain axis plays an important role in the development of depression. The aim of this study was to investigate the effects of 5-HT on cognitive function, learning and memory induced by chronic unforeseeable mild stress stimulation (CUMS) in female mice. CUMS mice and TPH2 KO mice were used in the study. Lactococcus lactis E001-B-8 fungus powder was orally administered to mice with CUMS.

METHODS

We used the open field test, Morris water maze, tail suspension test and sucrose preference test to examine learning-related behaviours. In addition, AB-PAS staining, immunofluorescence, ELISA, qPCR, Western blotting and microbial sequencing were employed to address our hypotheses.

RESULTS

The effect of CUMS was more obvious in female mice than in male mice. Compared with female CUMS mice, extracellular serotonin levels in TPH2 KO CUMS mice were significantly reduced, and cognitive dysfunction was aggravated. Increased hippocampal autophagy levels, decreased neurotransmitter levels, reduced oxidative stress damage, increased neuroinflammatory responses and disrupted gut flora were observed. Moreover, L. lactis E001-B-8 significantly improved the cognitive behaviour of mice.

CONCLUSIONS

These results strongly suggest that L. lactis E001-B-8 but not FLX can alleviate rodent depressive and anxiety-like behaviours in response to CUMS, which is associated with the improvement of 5-HT metabolism and modulation of the gut microbiome composition.

Exploring the role of ketone bodies in the diagnosis and treatment of psychiatric disorders

In recent times, advances in the field of metabolomics have shed greater light on the role of metabolic disturbances in neuropsychiatric conditions. The following review explores the role of ketone bodies and ketosis in both the diagnosis and treatment of three major psychiatric disorders: major depressive disorder, anxiety disorders, and schizophrenia. Distinction is made between the potential therapeutic effects of the ketogenic diet and exogenous ketone preparations, as exogenous ketones in particular offer a standardized, reproducible manner for inducing ketosis. Compelling associations between symptoms of mental distress and dysregulation in central nervous system ketone metabolism have been demonstrated in preclinical studies with putative neuroprotective effects of ketone bodies being elucidated, including effects on inflammasomes and the promotion of neurogenesis in the central nervous system. Despite emerging pre-clinical data, clinical research on ketone body effectiveness as a treatment option for psychiatric disorders remains lacking. This gap in understanding warrants further investigating, especially considering that safe and acceptable ways of inducing ketosis are readily available.

A novel conceptual model of trauma-informed care for patients with post-acute sequelae of SARS-CoV-2 illness (PASC)

AIM

This paper proposes a novel, trauma-informed, conceptual model of care for Post-Acute Sequelae of COVID-19 illness (PASC).

DESIGN

This paper describes essential elements, linkages and dimensions of the model that affect PASC patient experiences and the potential impact of trauma-informed care on outcomes.

DATA SOURCES

PASC is a consequence of the global pandemic, and a new disease of which little is known. Our model was derived from the limited available studies, expert clinical experience specific to PASC survivors and publicly available social media narratives authored by PASC survivors.

IMPLICATIONS FOR NURSING

The model provides a critical and novel framework for the understanding and care of persons affected by PASC. This model is aimed at the provision of nursing care, with the intention of reducing the traumatic impacts of the uncertain course of this disease, a lack of defined treatment options and difficulties in seeking care. The use of a trauma-informed care approach to PASC patients can enhance nurses' ability to remediate and ameliorate both the traumatic burden of and the symptoms and experience of the illness.

CONCLUSION

Applying a trauma-informed perspective to care of PASC patients can help to reduce the overall burden of this complex condition. Owing to the fundamentally holistic perspective of the nursing profession, nurses are best positioned to implement care that addresses multiple facets of the PASC experience.

IMPACT

The proposed model specifically addresses the myriad ways in which PASC may affect physical as well as mental and psychosocial dimensions of health. The model particularly seeks to suggest means of supporting patients who have already experienced a life-threatening illness and are now coping with its long-term impact. Since the scope of this impact is not yet defined, trauma-informed care for PASC patients is likely to reduce the overall health and systems burdens of this complex condition.

Carbon Dots Derived from Os Draconis and Their Anxiolytic Effect

Background

At present, people are susceptible to developing depression and anxiety disorders in response to stress. However, there is no specific medicine for anxiety. Os Draconis (OD, named "Long gu" in Chinese) are fossilized bones that have been used in traditional Chinese medicine to treat neurological diseases for thousands of years. Thus, we conducted this study to determine the biological basis for the anxiolytic effect of OD.

Methods

In this study, novel carbon dots (OD-CDs) from OD decoctions were discovered and separated. OD-CDs were anatomized using nanomaterials characterization methods to characterize the morphological structure, optical properties, and functional group properties. Four behavioural tests were conducted to observe the behavioural activities of mice, including the open field test (OFT), light/dark box test (LDT), elevated plus maze test (EPMT), and novelty-suppressed feeding test (NSFT), to determine its anxiolytic effects. Moreover, we assessed the possible mechanisms of the OD-CDs by detecting hormones associated with the hypothalamic-pituitary-adrenal (HPA) axis.

Results

OD-CDs were spherical and monodispersed with a narrow size distribution between 1 and 5 nm and had a yield of 3.67%. OD-CDs increased the activity time of mice in the central zone in the OFT. The mice in the experimental group showed more frequent activity in the light compartment and the open arms, in LDT and EPMT, respectively. In addition, OD-CDs shortened the feeding latency in the NSFT. Furthermore, the results after OD-CDs intervention showed a significant increase in serum serotonin (5-HT) and norepinephrine (NE). In addition, the concentrations of corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ATCH), and corticosterone (CORT) were decreased.

Conclusion

These results demonstrate a definite anxiolytic effect of OD-CDs and reveal the possible mechanism of action of OD-CDs' anxiolytic effect, which supports the research of OD for neurological disorders and a promising new trend of therapeutic approach and drug development.

Hyperinsulinemia Associated Depression

Hyperinsulinemia promotes fat accumulation, causing obesity. Being an inflammatory state, obesity can induce further inflammation and is a risk factor for HPA (hypothalamic pituitary axis) dysregulation through hypercortisolism-related hyperglycemia. In another hypothesis, the sympathetic nervous system (SNS) plays a significant role in the regulation of hormone secretion from the pancreas such as an increase in catecholamines and glucagon as well as a decrease in plasma insulin levels, a disruption on SNS activity increases insulin levels, and induces glycogenolysis in the liver and lipolysis in adipose tissue during hypoglycemia. Hyperglycemia-hyperinsulinemia exacerbates inflammation and increases the oxidative stress along with regulating the levels of norepinephrine in the brain sympathetic system. Increased inflammatory cytokines have also been shown to disrupt neurotransmitter metabolism and synaptic plasticity which play a role in the development of depression via inhibiting serotonin, dopamine, melatonin, and glutamate signaling. An increased level of plasma insulin over time in the absence of exercising causes accumulation of lipid droplets in hepatocytes and striated muscles thus preventing the movement of glucose transporters shown to result in an increase in insulin resistance due to obesity and further culminates into depression. Further hyperinsulinemia-hyperglycemia condition arising due to exogenous insulin supplementation for diabetes management may also lead to physiological hyperinsulinemia associated depression. Triple therapy with SSRI, bupropion, and cognitive behavioral therapy aids in improving glycemic control, lowering fasting blood glucose, decreasing the chances of relapse, as well as decreasing cortisol levels to improve cognition and the underlying depression. Restoring the gut microbiota has also been shown to restore insulin sensitivity and reduce anxiety and depression symptoms in patients.

The effects of music listening on somatic symptoms and stress markers in the everyday life of women with somatic complaints and depression

Despite a growing body of literature documenting the health-beneficial effects of music, empirical research on the effects of music listening in individuals with psychosomatic disorders is scarce. Using an ambulatory assessment design, we tested whether music listening predicts changes in somatic symptoms, subjective, and biological stress levels, and examined potential mediating processes, in the everyday life of 58 women (M = 27.7 years) with somatic symptom disorder (SSD) and depressive disorders (DEP). Multilevel models revealed that music listening predicted lower subjective stress ratings (p ≤ 0.02) irrespective of mental health condition, which, in turn, predicted lower somatic symptoms (p ≤ 0.03). Moreover, specific music characteristics modulated somatic symptoms (p = 0.01) and autonomic activity (p = 0.03). These findings suggest that music listening might mitigate somatic symptoms predominantly via a reduction in subjective stress in women with SSD and DEP and further inform the development of targeted music interventions applicable in everyday life.

A Retrospective Study of the Effects of Psychotropic Drugs on Neuroendocrine Hormones in Patients with Bipolar Disorder

BACKGROUND

Bipolar disorder (BD) is predominantly treated with medication, and previous studies have shown that psychotropic drugs have an effect on the neuroendocrine system. And the objectives of this study were: 1) to assess changes in neuroendocrine hormones of HPA axis and HPT axis in patients with BD after psychotropic drug treatment; 2) to determine differences in the above neuroendocrine hormones between psychotropic drug monotherapy and polytherapy treated patients.

METHODS

This study was a retrospective study that included 188 subjects.

RESULTS

After psychotropic drugs treatment, TSH levels increased significantly from baseline (p<0.001) and FT3, TT3, FT4, TT4, ACTH and CORT levels decreased significantly from baseline (p<0.001, p<0.001, p<0.001, p=0.007, p=0.039, p=0.031). There was no significant difference in hormonal changes between the monotherapy group and the polytherapy group, even though the polytherapy group was further divided into 4 subgroups. And there was no correlation between changes in hormones and treatment duration.

CONCLUSION

Although the incidence of significant HPT axis and HPA axis dysfunction after psychotropic drug treatment is low in patients with BD who have normal baseline neuroendocrine hormone levels, psychotropic drug treatment does suppress HPT axis and HPA axis function irrespective of the use of psychotropic drugs alone or in combination, and duration of psychotropic drug treatment. Therefore, even patients with BD who have normal baseline levels of neuroendocrine hormones should have their neuroendocrine hormone levels regularly monitored after psychotropic drug medication. But, the interval of monitoring can be slightly longer, which can be once every six months after taking psychotropic drugs.

Role of insulin-like growth factor 1, sex and corticosteroid hormones in male major depressive disorder

BACKGROUND

Hormones of the hypothalamic-pituitary-gonadal (HPG), hypothalamic-pituitary-adrenal (HPA), and hypothalamic-pituitary-somatotropic (HPS) axes are potentially involved in major depressive disorder (MDD), but these hormones have not been simultaneously investigated in male patients with MDD. We investigated the association between male MDD symptoms and estradiol, testosterone, cortisol, dehydroepiandrosterone sulfate (DHEAS), and insulin-like growth factor 1 (IGF1).

METHODS

Serum estradiol, testosterone, cortisol, DHEAS, and IGF1 levels were measured in 54 male patients with MDD and 37 male controls and were compared with clinical factors. We investigated the associations between hormone levels and Hamilton Depression Rating Scale (HAM-D) scores. The correlations among hormones were also investigated.

RESULTS

Patients had significantly lower estradiol levels than controls (22.4 ± 8.4 pg/mL vs. 26.1 ± 8.5 pg/mL, P = 0.040). Serum estradiol levels were negatively correlated with HAM-D scores (P = 0.000094) and positively correlated with Global Assessment of Functioning scores (P = 0.000299). IGF1 levels and the cortisol:DHEAS ratio were higher in patients than in controls (IGF1: 171.5 ± 61.8 ng/mL vs. 144.1 ± 39.2 ng/mL, P = 0.011; cortisol:DHEAS ratio: 0.07 ± 0.05 vs. 0.04 ± 0.02, P = 0.001). DHEAS levels were lower in patients than in controls (227.9 ± 108.4 μg/dL vs. 307.4 ± 131.2 μg/dL, P = 0.002). IGF1, cortisol:DHEAS ratio, and DHEAS were not significantly correlated with HAM-D scores. Cortisol and testosterone levels were not significantly different between patients and controls. Serum estradiol levels were positively correlated with DHEAS levels (P = 0.00062) in patients, but were not significantly correlated with DHEAS levels in controls.

CONCLUSION

Estradiol may affect the pathogenesis and severity of patients with MDD in men, and other hormones, such as those in the HPA and HPS axes, may also be involved in male MDD. Additionally, a correlation between estradiol and DHEAS may affect the pathology of MDD in men.

Effects of Psychotropics on the Microbiome in Patients With Depression and Anxiety: Considerations in a Naturalistic Clinical Setting

BACKGROUND

The antibacterial effects of psychotropics may be part of their pharmacological effects when treating depression. However, limited studies have focused on gut microbiota in relation to prescribed medication.

METHOD

We longitudinally investigated the relationship between patients' prescribed medications and intestinal bacterial diversity in a naturalistic treatment course for patients with major depressive disorders and anxiety disorders. Patients were recruited and their stool was collected at 3 time points during their usual psychiatric treatments. Gut microbiota were analyzed using 16S rRNA gene sequencing. We examined the impact of psychotropics (i.e., antidepressants, anxiolytics, antipsychotics) on their gut microbial diversity and functions.

RESULTS

We collected 246 stool samples from 40 patients. Despite no differences in microbial diversity between medication groups at the baseline, over the course of treatment, phylogenic diversity whole-tree diversity decreased in patients on antipsychotics compared with patients without (P = .027), and beta diversity followed this trend. Based on a fixed-effect model, antipsychotics predicted microbial diversity; the higher doses correlated with less diversity based on the Shannon index and phylogenic diversity whole tree (estimate = -0.00254, SE = 0.000595, P < .0001; estimate = -0.02644, SE = 0.00833, P = .002, respectively).

CONCLUSION

Antipsychotics may play a role in decreasing the alpha diversity of the gut microbiome among patients with depression and anxiety, and our results indicate a relationship with medication dosage. Future studies are warranted and should consider patients' types and doses of antipsychotics in order to further elucidate the mechanisms of gut-brain interactions in psychiatric disorders.

Increased methylation of NR3C1 and SLC6A4 is associated with blunted cortisol reactivity to stress in major depression

Background

Epigenetic changes are considered the main mechanisms behind the interplay of environment and genetic susceptibility in major depressive disorder (MDD). However, studies focusing on epigenetic dysregulation of the HPA axis stress response in MDD are lacking. Our objective was to simultaneously asses DNA methylation of the glucocorticoid receptor gene (NR3C1) and serotonin transporter gene (SLC6A4) and HPA axis response to stress in MDD.

Methods

We recruited 80 depressed inpatients and 58 gender and age matched healthy controls. All participants underwent the Trier Social Stress Test (TSST) and salivary cortisol was repeatedly measured to assess HPA axis reactivity. DNA methylation of the NR3C1 (exon 1 F) and SLC6A4 CpG islands was quantified from whole blood DNA. In the MDD group, clinical assessment was repeated at 8-week follow-up to test the predictive potential of DNA methylation for symptom improvement.

Results

Depressed patients had blunted cortisol reactivity to TSST compared to healthy controls (p = 0.01). In addition, they presented with increased average SLC6A4 (p = 0.003) and NR3C1 methylation (p = 0.03), as well as methylation of two individual NR3C1 CpG loci overlapping with the NGFI-A-binding sites (CpG12 and CpG20). Methylation of one of these two loci (CpG20) predicted lower symptom improvement at the follow-up (p = 0.007). Both, average NR3C1 and SLC6A4 methylation were associated with lower cortisol reactivity in the MDD group and explained about 16% of variability in cortisol response to TSST.

Conclusions

We provide evidence of the role of NR3C1 and SLC6A4 DNA methylation in HPA axis dysregulation in MDD, which needs to be further explored.

Effects of adolescent administration of fluoxetine on novel object recognition memory, anxiety-like behaviors, and hippocampal brain-derived neurotrophic factor level

AIMS

Fluoxetine (FLX) is a common selective serotonin reuptake inhibitor, which is used in adolescents with psychiatric disorders. Controversial results have been obtained in different studies about the effects of FLX on cognitive functions. The present study was designed to examine the effects of chronic FLX exposure during adolescence on cognitive function, anxiety-like behaviors, and hippocampal brain-derived neurotrophic factor (BDNF) mRNA expression among adult male and female rats.

MAIN METHODS

The sex-dependent effects of FLX chronic administration during adolescence (5 mg/kg/day, gavage) on short-term novel object recognition memory (NORM), anxiety-like behaviors, and BDNF mRNA expression in the hippocampus were examined. NORM and anxiety-like behaviors were assessed by novel object recognition, open field, and elevated plus-maze (EPM) tests, respectively. The expression of BDNF mRNA was also evaluated by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR).

KEY FINDINGS

The present findings revealed the dysfunction of short-term NORM among the adolescent male and female rats exposed to FLX, while the mRNA expression of BDNF was significantly higher among the males. Moreover, adolescent FLX administration had different effects on the anxiety-like behaviors of the male and female rats. Adolescent FLX treatment also decreased the body weight of the male animals.

SIGNIFICANCE

In conclusion, adolescent FLX treatment impairs cognitive functions in both sexes and increases BDNF mRNA expression in the hippocampus of the male animals. FLX administration during adolescence has sex-dependent effects on anxiety-like behaviors. These findings indicate that the impairment of cognitive functions can occur following the adolescent manipulation of the serotonergic system. Therefore, the side effects of chronic FLX administration during adolescence should be more considered.

The Link between Activities of Daily Living and Cortisol in Late-Life Depression

OBJECTIVES

Dysregulated cortisol in older individuals is associated with neurodegeneration and executive dysfunction, among other negative health outcomes. Executive functioning deficits are believed to underlie declines in functioning among older adults. Despite these associations, there is limited research examining the relationship between cortisol and impaired functional status.

METHODS

The present study examined the relationship between cortisol and functional status in a community sample of 51 older adults with depression. Pearson correlations and ordinal regressions were used to determine whether greater cortisol dysregulation was associated with ADL and IADL impairment.

RESULTS

Results indicated that individuals who had higher levels of cortisol also tended to demonstrate greater functional deficits. These findings remained true when functional status was measured by either a clinician-rated tool or a self-report measure.

CONCLUSIONS

The results of this study provide preliminary support for the hypothesis that elevated cortisol, in the context of depression, is associated with functional status deficits in older adults.

CLINICAL IMPLICATIONS

Findings from this study begin to fill the gap in research examining the relationship between cortisol and functional impairment in older adults and suggest that unique information can be gathered with the use of different functional status measures.

Rx risk or resistance? Psychotropic medication use in relation to physiological and psychosocial functioning of psychiatric hospital workers

To avoid methodological biases, psychoneuroendocrine studies have generally excluded psychotropic medication users. In workplace stress research, this has limited our ability to understand how psychotropic medication use affects many stress-related measures of interest. In this exploratory study, the effects of psychotropic medication use on stress physiology, occupational stress, and mental health were measured in a sample of healthy adult psychiatric hospital workers (N = 203, 70 % women). Diurnal cortisol was assessed on two non-consecutive work-days at five time-points (e.g., awakening, thirty minutes after awakening, 2 P M, 4 P M and bedtime). Cortisol reactivity was assessed by exposing participants to the Trier Social Stress Test. An allostatic load index was constructed using 19 neuroendocrine, immune, cardiovascular, and metabolic biomarkers. Occupational stress (e.g., job strain, effort-reward imbalance) and psychiatric symptoms (e.g., depression, burnout) were assessed with well-validated self-reports. Results showed that psychotropic medication use had no significant effects on diurnal cortisol profiles; however, psychotropic users had significantly decreased cortisol reactivity to the Trier Social Stress Test and higher allostatic load. Psychotropic users also had decreased effort-reward imbalance, but not job strain. Depressive symptoms did not differ between psychotropic medications users and non-users; however, burnout symptoms were higher among psychotropic medication users than non-users. Taken together, our findings do not warrant the systematic exclusion of psychotropic medication users from psychoneuroendocrine studies if insights into individual differences are sought among workers and other populations exposed to elevated stress.

Extent of cortisol suppression at baseline predicts improvement in HPA axis function during antidepressant treatment

BACKGROUND

A dysregulation in the hypothalamic-pituitary-adrenal (HPA)-axis function has been repeatedly observed in major depressive disorders (MDD). Normalization of this dysregulation, i.e. of cortisol suppression after glucocorticoid receptor (GR)-stimulation, may be mandatory for clinical remission in some patient subgroups. However, there are no biological measures applied in the clinical setting to identify patient subgroups with HPA axis alterations.

OBJECTIVE

We aimed to define a suppression index of cortisol concentrations before and after GR stimulation with dexamethasone to predict the variability in improvement of HPA axis activity during antidepressant treatment.

METHODS

A modified dexamethasone suppression test (mDST) was performed with blood withdrawal for cortisol and ACTH measurement before and 3 h after 1.5 mg dexamethasone intake at 18:00 in two cohorts of depressed patients treated in a naturalistic setting. The discovery sample consisted of 106 patients, the replication sample of 117 patients. The suppression index was defined as cCORTpreDEXcCORTpostDEX.

RESULTS

The baseline suppression index explained 27.4 % of the variance in changes of HPA axis activity before and after treatment with antidepressants. Age, cCORTpreDEXcACTHpreDEX at baseline and sex explained further variance up to 56.2 % (stepwise linear regression, p = 7.8e^-8). A threshold of the suppression index at baseline was determined by ROC analysis and revealed, that only patients with a maximum index of 2.32 achieved a normalization of the HPA axis activity after antidepressant treatment. In the replication sample, the threshold was 2.86. However, the estimated suppression index was not associated with treatment response.

CONCLUSION

For the first time, by establishing a short-term suppression index of cortisol before and after GR-stimulation a threshold could be identified to predict improvement of HPA axis activity during antidepressant therapy. After replication in further studies this index may help to identify patients who benefit from a specific treatment that targets components of the HPA axis in the future.

Psychotropic medication effects on cortisol: Implications for research and mechanisms of drug action

Stress and the hypothalamic-pituitary-adrenal (HPA) axis have been implicated in the etiology of a range psychiatric disorders; abnormalities in cortisol secretion are well documented in mood, anxiety, and psychotic disorders. There is, however, evidence that psychotropic medications affect HPA function, and are often a confound in research on the relation of cortisol secretion with psychiatric symptoms and syndromes. Psychotropic effects are particularly problematic in longitudinal research on individuals at clinical high risk (CHR) for serious mental illness, because they have the potential to obscure neurobiological mechanisms involved in crossing the threshold from CHR states to clinical disorders. This paper reviews the research literature on the relation of cortisol secretion with the three major classes of psychotropic medication that are most often prescribed; antipsychotics, antidepressants, and stimulants. The studies included in this review are those that measured both baseline and post-treatment cortisol. Taken together, most studies of antidepressants find that they are associated with a reduction in both basal and post-dexamethasone-CRH (DEX/CRH) cortisol, although some report no change. Similarly, antipsychotics, both typical and atypical, are found to reduce basal and DEX/CRH cortisol levels in most studies. Psychostimulant medications, in contrast, are associated with an increase in basal cortisol levels or no change. Effects of psychotropics on the cortisol awakening response (CAR) are less consistent. Implications of these effects for clinical research, especially studies of CHR populations, are discussed. Limitations of the research, due to variations in sample demographic and methodologic factors, are noted, and directions for future research are proposed.

Salivary cortisol as predictor for depression characteristics and remission in electroconvulsive therapy in older persons

Objectives: Electroconvulsive therapy (ECT) is the most effective treatment for depression; however, consensus on predictors for ECT outcome is lacking. We aim to examine the relation between pre-ECT salivary cortisol values and clinical characteristics and ECT outcome in depressed, older persons.Methods: A total of 102 inpatients meeting DSM-IV criteria for depression and referred for ECT were selected. Salivary cortisol was assessed at five time points during the day, providing insight into the cortisol awakening curve to the ground (AUCg) and to the increase (AUCi) and evening cortisol level. Depression severity was assessed using the Montgomery-Asberg Depression Rating Scale (MADRS). Remission was defined as MADRS <10; response was defined as MADRS-reduction of at least 50%. Regression analysis was used to assess associations between cortisol and (1) clinical variables, including depression severity, psychomotor symptoms and presence of psychosis, and (2) ECT outcome.Results: No significant relations were found between AUCg, AUCi, evening cortisol and depression severity, psychomotor symptoms, and presence of psychosis. In addition, no significant relation was found between cortisol and response or remission.Conclusions: Our results do not support a relation between cortisol values and depression characteristics, or ECT outcome in severely depressed, older patients treated with ECT.

Cortisol is not associated with pre-treatment medial temporal lobe volume or volume changes after electroconvulsive therapy in patients with late-life depression

Accumulating evidence suggests that late-life depression is associated with reduced hippocampal volume and that cortisol might be related to this volumetric reduction. We explored whether cortisol awaking response (CAR), which is the increase in cortisol after awakening, was associated with volumetric changes in the medial temporal lobe (MTL) after electroconvulsive therapy (ECT) in 41 patients (age ≥ 55) treated for major depressive disorder (MDD) with ECT. Cortisol was measured before the start of the ECT treatment and was related to MTL volumes derived from structural T1-weighted images. The study assessed associations between CAR and pre-treatment MTL volumes, and CAR and ECT-induced MTL volumetric changes. There were no significant correlations found between CAR, operationalized as Area Under the Curve with respect to ground (AUCg) and Area Under the Curve with respect to increase (AUCi), and pre-treatment MTL volumes. Neither was there an association between AUCg or AUCi and the ECT-induced changes in MTL volumes after correction for multiple comparisons. Finally, neither AUCg or AUCi were able to predict ECT-induced volumetric changes in the MTL. Hence, we conclude that CAR is unrelated to pre-treatment hippocampus and amygdala volumes, and to the volumetric changes in the aforementioned areas following ECT.

Chronic Atypical Depression as an Early Feature of Pituitary Adenoma: A Case Report and Literature Review

Pituitary adenomas are often diagnosed as incidental findings on brain imaging. We present the case of a 52-year-old African American female patient with long standing depressed mood prior to the incidental finding of a pituitary adenoma. We explore the possibility of certain mood symptoms prompting an early diagnosis of pituitary adenoma.

Social Support as a Mediator Between Insomnia and Depression in Female Undergraduate Students

Objectives/Background: Despite findings that insomnia and depression have a bidirectional relationship, the exact psychological mechanisms that link these disorders are largely unknown. The goal of this study was to identify whether social support mediates the relationship between insomnia and depression. Methods: The study sample (N = 115) consisted of females only, and all participants (mean age 21.77 ± 1.80) completed self-report measures of insomnia severity, depression, and social support. Results: Insomnia severity was significantly associated with low levels of social support (B = -1.04, SE = .27, p < .001) and high levels of depression (B = .18, SE = 0.05, p < .001). Social support mediated the effects of insomnia on depression (95% CI [.03, .15]). However, social support did not mediate the effects of depression on insomnia (95% CI [-.01, .32]). Conclusions: These findings suggest that interpersonal factors such as social support may be an important factor to consider in female insomnia patients in the context of preventing depression in this population.

The Impact of Stress and Major Depressive Disorder on Hippocampal and Medial Prefrontal Cortex Morphology

Volumetric reductions in the hippocampus and medial prefrontal cortex (mPFC) are among the most well-documented neural abnormalities in major depressive disorder (MDD). Hippocampal and mPFC structural reductions have been specifically tied to MDD illness progression markers, including greater number of major depressive episodes (MDEs), longer illness duration, and nonremission/treatment resistance. Chronic stress plays a critical role in the development of hippocampal and mPFC deficits, with some studies suggesting that these deficits occur irrespective of MDE occurrence. However, preclinical and human research also points to other stress-mediated neurotoxic processes, including enhanced inflammation and neurotransmitter disturbances, which may require the presence of an MDE and contribute to further brain structural decline as the illness advances. Specifically, hypothalamic-pituitary-adrenal axis dysfunction, enhanced inflammation and oxidative stress, and neurotransmitter abnormalities (e.g., serotonin, glutamate, gamma-aminobutyric acid) likely interact to facilitate illness progression in MDD. Congruent with stress sensitization models of MDD, with each consecutive MDE it may take lower levels of stress to trigger these neurotoxic pathways, leading to more pronounced brain volumetric reductions. Given that stress and MDD have overlapping and distinct influences on neurobiological pathways implicated in hippocampal and mPFC structural decline, further work is needed to clarify which precise mechanisms ultimately contribute to MDD development and maintenance.

Altered hippocampal function with preserved cognitive performance in treatment-naive major depressive disorder

The hippocampus is implicated in the pathophysiology of major depressive disorder (MDD), with evidence that morphological changes occur with disease progression. It was hypothesized that treatment-naive patients with depression would show performance deficits in hippocampus-dependent memory trials, with concurrent hippocampal activation deficits on functional magnetic resonance imaging, compared with control participants. Thirteen treatment-naive patients with MDD and 13 control participants completed a hippocampus-dependent memory functional magnetic resonance imaging process-dissociation task. On behavioural measures of habit memory and guessing, there were no significant differences between groups. Functional magnetic resonance imaging analysis indicated that compared with the control group, the MDD group showed increased activation in the parahippocampal gyrus and hippocampus on habit memory and nonitem trials. These alterations in hippocampal functioning with preserved cognitive performance on a test of hippocampus-dependent memory in MDD may be indicative of a compensatory mechanism.

Can physical exercise modulate cortisol level in subjects with depression? A systematic review and meta-analysis

INTRODUCTION

Major depressive disorder (MDD) is a prevalent medical illness that is associated with chronic stress. Patients with MDD can show an imbalance in cortisol levels, which can be restored with the remission of symptoms. Physical exercise training has been used as a tool to promote changes in cortisol levels in healthy individuals. However, it is unknown if exercise can produce the same results in individuals with MDD.

OBJECTIVE

To review evidence of cortisol changes after exercise training in individuals with MDD.

METHODS

We conducted a search on PubMed, SciELO, LILACS, ISI Web of Knowledge, Scopus, and PsycInfo databases. Random effects meta-analysis was performed and standardized mean difference (SMD) effect size was calculated. Analyses of forest and funnel plots was conducted using Stata v.11.0 software.

RESULTS

At first, 463 studies were obtained in the search. After completion of the selection procedure, five articles with seven analyses were included. Type of exercise, frequency of training, cortisol measurement, and type of control group were analyzed. There was a reduction of cortisol levels in the exercise group (SMD = -0.65, 95%CI 1.30-0.01). Moreover, sensitivity analysis and subgroup analyses revealed an effect of type (aerobic exercise) and frequency (five times per week) of exercise on reduction of cortisol levels. However, these results should be interpreted cautiously due to the small number of studies and a substantial heterogeneity among them.

CONCLUSION

Physical exercise promotes a reduction in cortisol levels in individuals with MDD. However, this finding can be influenced by type of exercise, weekly frequency, and type of cortisol measurement.

The impact of acute mental stress on brachial artery flow-mediated dilation in women diagnosed with depression

Endothelial function, assessed by flow-mediated dilation (FMD), may be transiently attenuated in healthy adults following acute mental stress. However, the impact of acute mental stress on endothelial function in the context of clinical depression is unknown. This study examined the impact of acute mental stress on FMD in women with a diagnosis of a depressive disorder. Forty-three otherwise healthy women (33 ± 14 years) participated. Brachial artery diameter and blood velocity were assessed with ultrasound. FMD was assessed immediately prior to and 15 min following the Trier Social Stress Test (TSST). The FMD protocol included 5 min of forearm cuff occlusion (pressure = 250 mm Hg), followed by release. Shear stress was estimated by calculating shear rate (SR = brachial artery blood velocity/diameter). Stress reactivity was assessed via changes in mean arterial pressure (MAP), heart rate (HR) and salivary cortisol. Results are mean ± SD. A significant stress response was elicited by the TSST [MAP, HR and salivary cortisol increased (p < 0.05)]. Neither the SR stimulus nor FMD response differed pre-versus post-stress (p = 0.124 and p = 0.641, respectively). There was a modest negative correlation between cortisol reactivity and change in FMD from pre- to post-stress (R = -0.392, p = 0.011). To conclude, acute mental stress did not consistently impair endothelial function in women diagnosed with a depressive disorder; however, higher cortisol reactivity may increase the likelihood of post-stress endothelial dysfunction. Further research is required to better understand the factors influencing the relationship between acute mental stress, cortisol and endothelial function in women with depression.

Cortisol levels and cognitive profile in major depression: A comparison of currently and previously depressed patients

The association between depressive symptoms and elevated cortisol levels, and depression and cognitive functioning, has been less robust in outpatients with symptoms in the mild to moderate range. Furthermore, the association between elevated cortisol levels and cognitive functioning is unclear. In the present study, currently depressed (n = 37), previously depressed (n = 81) and never depressed controls (n = 50) were assessed on a range of neuropsychological measures. Salivary cortisol was measured in the morning and evening. Participants with current depression were non-hospitalized and had symptoms predominately in the mild to moderate range. Elevated salivary evening cortisol, but not morning cortisol, was significantly related to depressive symptoms. The difference in cortisol levels between the previously depressed group and the never depressed controls was not significant. The groups had significantly different cognitive profiles, with the currently depressed performing poorer on tasks related to working memory compared to the never depressed controls. Both the currently and previously depressed performed worse on attentional tasks. The findings indicate that outpatients with mild to moderate depression have elevated cortisol levels and limited mild cognitive impairments. Furthermore, mild impairments in attention may persist after remission, indicating that this could be a trait-marker in depression. The present study did not find support for a significant relationship between cortisol and cognitive functioning.

Neurobiology and Therapeutic Potential of Cyclooxygenase-2 (COX-2) Inhibitors for Inflammation in Neuropsychiatric Disorders

Neuropsychiatric disorders, such as depression, bipolar disorder, schizophrenia, obsessive-compulsive disorder, and neurodevelopmental disorders such as autism spectrum disorder, are associated with significant illness burden. Accumulating evidence supports an association between these disorders and inflammation. Consequently, anti-inflammatory agents, such as the cyclooxygenase-2 inhibitors, represent a novel avenue to prevent and treat neuropsychiatric illness. In this paper, we first review the role of inflammation in psychiatric pathophysiology including inflammatory cytokines' influence on neurotransmitters, the hypothalamic-pituitary-adrenal axis, and microglial mechanisms. We then discuss how cyclooxygenase-2-inhibitors influence these pathways with potential therapeutic benefit, with a focus on celecoxib, due to its superior safety profile. A search was conducted in PubMed, Embase, and PsychINFO databases, in addition to Clinicaltrials.gov and the Stanley Medical Research Institute trial registries. The results were presented as a narrative review. Currently available outcomes for randomized controlled trials up to November 2017 are also discussed. The evidence reviewed here suggests cyclooxygenase-2 inhibitors, and in particular celecoxib, may indeed assist in treating the symptoms of neuropsychiatric disorders; however, further studies are required to assess appropriate illness stage-related indication.

Increased adrenocorticotropic hormone (ACTH) levels predict severity of depression after six months of follow-up in outpatients with major depressive disorder

Previous studies have reported dysfunction in the hypothalamic-pituitary-adrenal (HPA) axis in patients with major depressive disorder (MDD). Outpatients diagnosed with MDD (n = 199) underwent psychological evaluation, and were followed up with a phone interview after 6 months, using the Patient Health Questionnaire (PHQ-9). At 6-month follow-up, 59 out of 199 patients with MDD were still depressed (29.5%), as shown by scores ≥ 10 on the PHQ-9. The depressed group at follow-up showed significantly higher anxiety and suicidality levels at baseline than the non-depressed group at follow-up. Among the complete blood counts, lipid profiles, and hormone levels, adrenocorticotropic hormone (ACTH) was the only parameter that was significantly increased in the still depressed group. Levels higher than 40 pg/mL of ACTH at baseline were associated with higher depression scores at follow-up. Multiple linear regression analyses revealed that ACTH and cortisol predicted depression scores at follow-up, after controlling for baseline depression scores. Increased ACTH level at baseline may predict ongoing symptoms and severity of depression at follow-up, suggesting the role of dysfunctional HPA axis in MDD prognosis.

A study of the relationship between adverse childhood experiences, life events, and executive function among college students in China

Objective

The aim of this study was to investigate the effects of adverse childhood experiences and life events on the inhibitory control ability, cognitive flexibility, and working memory of college students.

Methods

The study involved testing the participants using the Adverse Childhood Experiences (ACEs) Questionnaire, the Adolescent Life Events Scale (Adolescent Self-rating Life Events Checklist, ASLEC), and the program of executive functions designed by E-prime software.

Results

The incidence rate of ACEs was 44.8%. ACEs, life events, and inhibition ability were found to have a significant correlation (r1 = 0.50, r1 = 0.47, p < 0.01). In the switching task, the reaction time of the ACEs group was longer than the reaction time of the non-ACEs group (t = − 2.55, p < 0.05). Low scorers in the ASLEC exhibited lesser reaction times than their high-scoring counterparts in the tasks related to inhibition, switching, and working memory experiments. The regression analysis results showed that ACEs and life events had a possibility rate of 56% in predicting inhibition ability.

Conclusions

The incidence of ACEs was found to be high, and cognitive flexibility is significantly influenced by ACEs. Life events have a significant impact on inhibition ability, cognitive flexibility, and working memory. ACEs and life events were found to be reliable predictors of inhibition ability.

Defective Inflammatory Pathways in Never-Treated Depressed Patients Are Associated with Poor Treatment Response

Inflammation has been involved in the pathophysiology and treatment response of major depressive disorder (MDD). Plasma cytokine profiles of 171 treatment-naive MDD patients (none of the MDD patients received an adequate trial of antidepressants or evidence-based psychotherapy) and 64 healthy controls (HCs) were obtained. MDD patients exhibited elevated concentrations of 18 anti- and proinflammatory markers and decreased concentrations of 6 cytokines. Increased inflammasome protein expression was observed in MDD patients, indicative of an activated inflammatory response. The plasma of MDD patients was immunosuppressive on healthy donor peripheral blood mononuclear cells, inducing reduced activation of monocytes/dendritic cells and B cells and reduced T cell memory. Comparison between 33 non-responders and 71 responders at baseline and 12 weeks revealed that after treatment, anti-inflammatory cytokine levels increase in both groups, whereas 5 proinflammatory cytokine levels were stabilized in responders, but continued to increase in non-responders. MDD patients exhibit remodeling of their inflammatory landscape.

Electroconvulsive Therapy in Depression: Current Practice and Future Direction

The current practice of electroconvulsive therapy (ECT) has evolved over several decades with the implementation of safer equipment and advancement of techniques. In addition, modifications in the delivery of ECT, such as the utilization of brief and ultrabrief pulse widths and individualization of treatment parameters, have improved the safety of ECT without sacrificing efficacy. This article aims to provide psychiatrists with a balanced, in-depth look into the recent advances in ECT technique as well as the evidence of ECT for managing depression in special populations and patients with comorbid medical problems.

Electroconvulsive seizures influence dendritic spine morphology and BDNF expression in a neuroendocrine model of depression

BACKGROUND

Electroconvulsive therapy (ECT) is a rapid and effective treatment for major depressive disorder. Chronic stress-induced depression causes dendrite atrophy and deficiencies in brain-derived neurotrophic factor (BDNF), which are reversed by anti-depressant drugs. Electroconvulsive seizures (ECS), an animal model of ECT, robustly increase BDNF expression and stimulate dendritic outgrowth.

OBJECTIVE

The present study aims to understand cellular and molecular plasticity mechanisms contributing to the efficacy of ECS following chronic stress-induced depression.

METHODS

We quantify Bdnf transcript levels and dendritic spine density and morphology on cortical pyramidal neurons in mice exposed to vehicle or corticosterone and receiving either Sham or ECS treatment.

RESULTS

ECS rescues corticosterone-induced defects in spine morphology and elevates Bdnf exon 1 and exon 4-containing transcripts in cortex.

CONCLUSIONS

Dendritic spine remodeling and induction of activity-induced BDNF in the cortex represent important cellular and molecular plasticity mechanisms underlying the efficacy of ECS for treatment of chronic stress-induced depression.

The Dopamine Receptor D3 Regulates Lipopolysaccharide-Induced Depressive-Like Behavior in Mice

BACKGROUND

The altered expression and function of dopamine receptor D3 (D3R) in patients and animal models have been correlated with depression disease severity. However, the morphological alterations and biological effects of D3R in the brain after inflammation-induced depressive-like behavior remain elusive.

METHODS

In the present study, we ascertained the changes of D3R expression in the brain regions after depressive-like behavior induced by peripheral administration of lipopolysaccharide (LPS). Protein levels of proinflammatory cytokines, brain-derived neurotrophic factor (BDNF), and extracellular signal-regulated kinase (ERK1/2)-cAMP-response element-binding protein (CREB) signaling pathway after activation or inhibition of D3R in the brain of depressive mice were also investigated.

RESULTS

LPS caused a significant reduction of D3R in the ventral tegmental area (VTA), medial prefrontal cortex (mPFC), and nucleus accumbens (NAc), which are areas related to the mesolimbic dopaminergic system. Pretreatment with pramipexole (PPX), a preferential D3R agonist, showed antidepressant effects on LPS-induced depression-like behavior through preventing changes in LPS-induced proinflammatory cytokines (tumour necrosis factor-α, interleukin-1β, and interleukin-6), BDNF, and ERK1/2-CREB signaling pathway in the VTA and NAc. In opposition, treatment with a D3R selective antagonist NGB 2904 alone made mice susceptible to depression-like effects and caused changes in accordance with the LPS-induced alterations in proinflammatory cytokines, BDNF, and the ERK1/2-CREB signaling pathway in the mPFC and NAc.

CONCLUSIONS

These findings provide a relevant mechanism for D3R in LPS-induced depressive-like behavior via its mediation of proinflammatory cytokines and potential cross-effects between BDNF and the ERK1/2-CREB signaling pathway.

Roles of Inflammation and Depression in the Development of Gestational Diabetes

Inflammation, the body's response to harmful external agents, has long been found to be associated with depressive symptoms. The relationship between inflammation and depression is well established in the general population of people with depression, but is less so among perinatal women. Depression in the perinatal period is a common disorder, however available data do not indicate that there is a specific inflammatory picture associated with perinatal depression. We suggest that perinatal depression may be a heterogeneous construct, and that inflammation may be relevant to it in the context of other inflammatory morbidities of pregnancy. In this review we explore the available support for the hypothesis that inflammation associated with depression can represent a precipitating insult for the development of gestational diabetes, a known inflammatory morbidity of pregnancy.

New directions in the rational design of electrical and magnetic seizure therapies: individualized Low Amplitude Seizure Therapy (iLAST) and Magnetic Seizure Therapy (MST)

Electroconvulsive therapy remains a key treatment option for severe cases of depression, but undesirable side-effects continue to limit its use. Innovations in the design of novel seizure therapies seek to improve its risk benefit ratio through enhanced control of the focality of stimulation. The design of seizure therapies with increased spatial precision is motivated by avoiding stimulation of deep brain structures implicated in memory retention, including the hippocampus. The development of two innovations in seizure therapy-individualized low-amplitude seizure therapy (iLAST) and magnetic seizure therapy (MST), are detailed. iLAST is a method of seizure titration involving reducing current spread in the brain by titrating current amplitude from the traditional fixed amplitudes. MST, which can be used in conjunction with iLAST dosing methods, involves the use of magnetic stimulation to reduce shunting and spreading of current by the scalp occurring during electrical stimulation. Evidence is presented on the rationale for increasing the focality of ECT in hopes of preserving its effectiveness, while reducing cognitive side-effects. Finally, the value of electric field and neural modelling is illustrated to explain observed clinical effects of modifications to ECT technique, and their utility in the rational design of the next generation of seizure therapies.

Cortisol dysregulation: the bidirectional link between stress, depression, and type 2 diabetes mellitus

Controversy exists over the role of stress and depression in the pathophysiology of type 2 diabetes mellitus. Depression has been shown to increase the risk for progressive insulin resistance and incident type 2 diabetes mellitus in multiple studies, whereas the association of stress with diabetes is less clear, owing to differences in study designs and in forms and ascertainment of stress. The biological systems involved in adaptation that mediate the link between stress and physiological functions include the hypothalamic-pituitary-adrenal (HPA) axis and the autonomic nervous and immune systems. The HPA axis is a tightly regulated system that represents one of the body's mechanisms for responding to acute and chronic stress. Depression is associated with cross-sectional and longitudinal alterations in the diurnal cortisol curve, including a blunted cortisol awakening response and flattening of the diurnal cortisol curve. Flattening of the diurnal cortisol curve is also associated with insulin resistance and type 2 diabetes mellitus. In this article, we review and summarize the evidence supporting HPA axis dysregulation as an important biological link between stress, depression, and type 2 diabetes mellitus.

Major depressive disorder

Major depressive disorder (MDD) is a debilitating disease that is characterized by depressed mood, diminished interests, impaired cognitive function and vegetative symptoms, such as disturbed sleep or appetite. MDD occurs about twice as often in women than it does in men and affects one in six adults in their lifetime. The aetiology of MDD is multifactorial and its heritability is estimated to be approximately 35%. In addition, environmental factors, such as sexual, physical or emotional abuse during childhood, are strongly associated with the risk of developing MDD. No established mechanism can explain all aspects of the disease. However, MDD is associated with alterations in regional brain volumes, particularly the hippocampus, and with functional changes in brain circuits, such as the cognitive control network and the affective-salience network. Furthermore, disturbances in the main neurobiological stress-responsive systems, including the hypothalamic-pituitary-adrenal axis and the immune system, occur in MDD. Management primarily comprises psychotherapy and pharmacological treatment. For treatment-resistant patients who have not responded to several augmentation or combination treatment attempts, electroconvulsive therapy is the treatment with the best empirical evidence. In this Primer, we provide an overview of the current evidence of MDD, including its epidemiology, aetiology, pathophysiology, diagnosis and treatment.

In search of the HPA axis activity in unipolar depression patients with childhood trauma: Combined cortisol awakening response and dexamethasone suppression test

The aim of the present study was to examine the impact of childhood trauma on HPA axis activity both in depression patients and healthy controls in order to determine the role of HPA axis abnormalities in depression and to find the differences in HPA axis functioning that may lead certain individuals more susceptible to the depressogenic effects of childhood trauma. Eighty subjects aged 18-45 years were recruited into four study groups (n = 18, depression patients with childhood trauma exposures, CTE/MDD; n = 17, depression patients without childhood adversity, non-CTE/MDD; n = 23, healthy persons with childhood trauma, CTE/non-MDD; and n = 22, healthy persons without childhood adversity, non-CTE/non-MDD). Each participant collected salivary samples in the morning at four time points: immediately upon awakening, 30, 45, and 60 min after awakening for the assessment of CAR and underwent a 1 mg-dexamethasone suppression test (DST). Regardless of depression, subjects with CTE exhibited an enhanced CAR and the CAR areas under the curve to ground (AUCg) were associated with their childhood trauma questionnaire (CTQ) physical neglect scores and CTQ total scores. In addition, the CTE/MDD group also showed a highest post-DST cortisol concentration and a decreased glucocorticoid feedback inhibition among four groups of subjects. The present findings suggested that childhood trauma was associated with hyperactivity of HPA axis as measured with CAR, potentially reflecting the vulnerability for developing depression after early life stress exposures. Moreover, dysfunction of the GR-mediated negative feedback control might contribute to the development of depression after CTE.

The HPA axis in bipolar disorder: Systematic review and meta-analysis

OBJECTIVES

To provide a quantitative and qualitative synthesis of the available evidence on the role of Hypothalamic-Pituitary-Adrenal (HPA) axis in the pathophysiology of Bipolar Disorder (BD).

METHODS

Meta-analysis and meta-regression of case-control studies examining the levels of cortisol, ACTH, CRH levels. Systematic review of stress reactivity, genetic, molecular and neuroimaging studies related to HPA axis activity in BD.

RESULTS

Forty-one studies were included in the meta-analyses. BD was associated with significantly increased levels of cortisol (basal and post-dexamethasone) and ACTH, but not of CRH. In the meta-regression, case-control differences in cortisol levels were positively associated with the manic phase (p=0.005) and participants' age (p=0.08), and negatively with antipsychotics use (p=0.001). Reviewed studies suggest that BD is associated with abnormalities of stress-related molecular pathways in several brain areas. Variants of HPA axis-related genes seem not associated with a direct risk of developing BD, but with different clinical presentations. Also, studies on unaffected relatives suggest that HPA axis dysregulation is not an endophenotype of BD, but seems related to environmental risk factors, such as childhood trauma. Progressive HPA axis dysfunction is a putative mechanism that might underlie the clinical and cognitive deterioration of patients with BD.

CONCLUSIONS

BD is associated with dysfunction of HPA axis activity, with important pathophysiological implications. Targeting HPA axis dysfunctions might be a novel strategy to improve the outcomes of BD.

Examining the role of neuroinflammation in major depression

Recent findings have established a connection between inflammation and major depression and specifically the role of the hypothalamic-pituitary-adrenal (HPA) axis in depression. This article reviews clinical and experimental studies examining the role of the HPA axis, HPA hyperactivity (resulting in increased cortisol levels), as well as the proinflammatory cytokines tumor necrosis factor, C-reactive protein, and the interleukins, in depressed patients. Similarly this paper will review data supporting increased cytokine levels in depression and specifically differential effects in treatment-resistant patients, as well as potentially distinguishing in particular depression subtypes. Understanding the role of the immune system and inflammation in patients with major depression is essential in order to develop efficacious treatments potentially targeting inflammation in relation to the depression in order to reduce patient symptomatology and comorbidities.

Multilevel assessment of the neurobiological threat system in depressed adolescents: interplay between the limbic system and hypothalamic-pituitary-adrenal axis

Integrative, multilevel approaches investigating neurobiological systems relevant to threat detection promise to advance understanding of the pathophysiology of major depressive disorder (MDD). In this study we considered key neuronal and hormonal systems in adolescents with MDD and healthy controls (HC). The goals of this study were to identify group differences and to examine the association of neuronal and hormonal systems. MDD and HC adolescents (N = 79) aged 12-19 years were enrolled. Key brain measures included amygdala volume and amygdala activation to an emotion face-viewing task. Key hormone measures included cortisol levels during a social stress task and during the brain scan. MDD and HC adolescents showed group differences on amygdala functioning and patterns of cortisol levels. Amygdala activation in response to emotional stimuli was positively associated with cortisol responses. In addition, amygdala volume was correlated with cortisol responses, but the pattern differed in depressed versus healthy adolescents, most notably for unmedicated MDD adolescents. The findings highlight the value of using multilevel assessment strategies to enhance understanding of pathophysiology of adolescent MDD, particularly regarding how closely related biological threat systems function together while undergoing significant developmental shifts.