The role of mineralocorticoid receptor function in treatment-resistant depression

Hypothalamic-pituitary-adrenal axis hyperactivity is normalized after successful intermittent theta-burst stimulation in resistant depressed patients

The present pilot study assessed the effects of multi-session intermittent theta-burst stimulation (iTBS) applied to the left dorsolateral prefrontal cortex in 17 treatment resistant depressed inpatients (TRDs) showing cortisol non-suppression to the overnight dexamethasone suppression test (DST) at baseline (i.e., maximum post-DST cortisol [CORmax] level > 130 nmol/L). After 20 iTBS sessions, the DST was repeated in all TRDs. At baseline, post-DST CORmax levels were higher in TRDs compared to healthy control subjects (HCs; n = 17) (p < 0.0001). After 20 iTBS sessions, post-DST CORmax levels decreased from baseline (p < 0.03) and were comparable to HCs. Decreases in post-DST CORmax levels were related to decreases in 17-item Hamilton Depression Rating Scale (HAMD-17) scores (ρ = 0.53; p < 0.03). At endpoint, 10 TRDs showed DST normalization (among them 7 were responders [i.e., HAMD-17 total score > 50% decrease from baseline]), and 7 did not normalize their DST (among them 6 were non-responders) (p < 0.05). Our results suggest that successful iTBS treatment may restore normal glucocorticoid receptor feedback inhibition at the pituitary level.

Sildenafil, alone and in combination with imipramine or escitalopram, display antidepressant-like effects in an adrenocorticotropic hormone-induced (ACTH) rodent model of treatment-resistant depression

BACKGROUND

Major depressive disorder (MDD) represents a challenge with high prevalence and limited effectiveness of existing treatments, particularly in cases of treatment-resistant depression (TRD). Innovative strategies and alternative drug targets are therefore necessary. Sildenafil, a selective phosphodiesterase type 5 (PDE5) inhibitor, is known to exert neuroplastic, anti-inflammatory, and antioxidant properties, and is a promising antidepressant drug candidate.

AIM

To investigate whether sildenafil monotherapy or in combination with a known antidepressant, can elicit antidepressant-like effects in an adrenocorticotropic hormone (ACTH)-induced rodent model of TRD.

METHODS

ACTH-naïve and ACTH-treated male Sprague-Dawley (SD) rats received various sub-acute drug treatments, followed by behavioural tests and biochemical analyses conversant with antidepressant actions.

RESULTS

Sub-chronic ACTH treatment induced significant depressive-like behaviour in rats, evidenced by increased immobility during the forced swim test (FST). Sub-acute sildenafil (10 mg/kg) (SIL-10) (but not SIL-3), and combinations of imipramine (15 mg/kg) (IMI-15) and sildenafil (3 mg/kg) (SIL-3) or escitalopram (15 mg/kg) (ESC-15) and SIL-3, exhibited significant antidepressant-like effects. ACTH treatment significantly elevated hippocampal levels of brain-derived neurotrophic factor (BDNF), serotonin, norepinephrine, kynurenic acid (KYNUA), quinolinic acid (QUINA), and glutathione. The various mono- and combined treatments significantly reversed some of these changes, whereas IMI-15 + SIL-10 significantly increased glutathione disulfide levels. ESC-15 + SIL-3 significantly reduced plasma corticosterone levels.

CONCLUSION

This study suggests that sildenafil shows promise as a treatment for TRD, either as a stand-alone therapy or in combination with a traditional antidepressant. The neurobiological mechanism underlying the antidepressant-like effects of the different sildenafil mono- and combination therapies reflects a multimodal action and cannot be explained in full by changes in the individually measured biomarker levels.

The Hypothalamus-Pituitary-Adrenal Axis and Social Cognition in Borderline Personality Disorder

Borderline personality disorder (BPD) is characterized by emotional instability, impulsivity and unstable interpersonal relationships. Patients experience discomforting levels of distress, inducing symptoms like dissociation, aggression or withdrawal. Social situations are particularly challenging, and acute social stress can reduce patients' cognitive and social functioning. In patients with Major Depressive Disorder or Posttraumatic Stress Disorder, which show high comorbidity with BPD, the endocrine stress response is characterized by Hypothalamus-Pituitary-Adrenal (HPA) axis dysfunction, which affects cognitive functioning. Compared to these clinical groups, research on HPA-axis function in BPD is relatively scarce, but evidence points towards a blunted cortisol reactivity to acute stress. Since BPD patients are particularly prone to social stress and experience high subjective difficulties in these situations, it seems plausible that HPA-axis dysregulation might contribute to decreased social cognition in BPD. The present review summarizes findings on the HPA-axis function in BPD and its association with social cognition following acute social stress. For this purpose, we review literature that employed a widely used social stressor (Trier Social Stress Test, TSST) to study the effects of acute social stress on social cognition and the HPA-axis response. We contrast these findings with studies on social cognition that employed Cyberball, another widely used social stressor that lacks HPA-axis involvement. We conclude that research on social cognition in BPD reveals heterogeneous results with no clear relationship between social functioning and HPA-axis response. More research is needed to better understand the psychophysiological underpinnings of impaired social cognition in BPD.

Biological correlates of treatment resistant depression: a review of peripheral biomarkers

Introduction

Many patients fail to respond to multiple antidepressant interventions, being defined as "treatment-resistant depression" (TRD) patients. TRD is usually associated with increased severity and chronicity of symptoms, increased risk of comorbidity, and higher suicide rates, which make the clinical management challenging. Efforts to distinguish between TRD patients and those who will respond to treatment have been unfruitful so far. Several studies have tried to identify the biological, psychopathological, and psychosocial correlates of depression, with particular attention to the inflammatory system. In this paper we aim to review available studies assessing the full range of biomarkers in TRD patients in order to reshape TRD definition and improve its diagnosis, treatment, and prognosis.

Methods

We searched the most relevant medical databases and included studies reporting original data on possible biomarkers of TRD. The keywords "treatment resistant depression" or "TRD" matched with "biomarker," "inflammation," "hormone," "cytokine" or "biological marker" were entered in PubMed, ISI Web of Knowledge and SCOPUS databases. Articles were included if they included a comparison with healthy controls (HC).

Results

Of the 1878 papers identified, 35 were included in the present study. Higher plasma levels of IL-6 and TNF-α were detected in TRD patients compared to HC. While only a few studies on cortisol have been found, four papers showed elevated levels of C-reactive protein among these patients and four articles focused on immunological cells. Altered kynurenine metabolism in TRD patients was reported in two studies, while contrasting results were found with regard to BDNF.

Conclusion

Only a few biological alterations correlate with TRD. TNF-α seems to be the most relevant biomarker to discriminate TRD patients from both HC and treatment-responsive MDD patients. Moreover, several discrepancies among studies have been found, due to methodological differences and the lack of a standardized diagnostic definition of TRD.

The Role of the Adrenal-Gut-Brain Axis on Comorbid Depressive Disorder Development in Diabetes

Diabetic patients are more affected by depression than non-diabetics, and this is related to greater treatment resistance and associated with poorer outcomes. This increase in the prevalence of depression in diabetics is also related to hyperglycemia and hypercortisolism. In diabetics, the hyperactivity of the HPA axis occurs in parallel to gut dysbiosis, weakness of the intestinal permeability barrier, and high bacterial-product translocation into the bloodstream. Diabetes also induces an increase in the permeability of the blood-brain barrier (BBB) and Toll-like receptor 4 (TLR4) expression in the hippocampus. Furthermore, lipopolysaccharide (LPS)-induced depression behaviors and neuroinflammation are exacerbated in diabetic mice. In this context, we propose here that hypercortisolism, in association with gut dysbiosis, leads to an exacerbation of hippocampal neuroinflammation, glutamatergic transmission, and neuronal apoptosis, leading to the development and aggravation of depression and to resistance to treatment of this mood disorder in diabetic patients.

Early life stress, depression and epigenetics

Different factors are essential in increasing the vulnerability to psychiatric disorders, such as genetics. Among these factors, early life stress (ELS), including sexual, physical, emotional abuse, and emotional and physical neglect, enhances the odds of having menial conditions throughout life. Exhaustive research has shown that ELS leads to physiological changes, such as alteration in the HPA axis. During the most critical development period (childhood and adolescence), these changes increase the risk of having child-onset psychiatric disorders. Furthermore, research has suggested a relationship between early life stress and depression, particularly more prolonged episodes of depression with treatment-resistant outcomes. Molecular studies indicate that, in general, the hereditary character of psychiatric disorders is polygenic, multifactorial and highly complex, with innumerable low-effect genetic variants interacting with each other. However, whether there are independent effects among subtypes of ELS remains unclear. This article provides an overview of the interplay of epigenetics, the HPA axis, early life stress and the development of depression. Advances in our knowledge of epigenetics in the context of early life stress and depression provide a new understanding of the genetic influence on psychopathology. Furthermore, they could lead to identifying new targets for clinical intervention.

A viewpoint on aldosterone and BMI related brain morphology in relation to treatment outcome in patients with major depression

An abundance of knowledge has been collected describing the involvement of neuroendocrine parameters in major depression. The hypothalamic-pituitary-adrenocortical (HPA) axis regulating cortisol release has been extensively studied; however, attempts to target the HPA axis pharmacologically to treat major depression have failed. This review focuses on the importance of the adrenocortical stress hormone aldosterone, which is released by adrenocorticotropic hormone and angiotensin, and the mineralocorticoid receptor (MR) in depression. Depressed patients, in particular those with atypical depression, have signs of central hyperactivation of the aldosterone sensitive MR, potentially as a consequence of a reactive aldosterone release induced by low blood pressure and as a result of low sensitivity of peripheral MR. This is reflected in reduced heart rate variability, increased salt appetite and sleep changes in this group of patients. In addition, enlarged brain ventricles, compressed corpus callosum and changes of the choroid plexus are associated with increased aldosterone (in relation to cortisol). Furthermore, subjects with these features often show obesity. These characteristics are related to a worse antidepressant treatment outcome. Alterations in choroid plexus function as a consequence of increased aldosterone levels, autonomic dysregulation, metabolic changes and/or inflammation may be involved. The characterization of this regulatory system is in its early days but may identify new targets for therapeutic interventions.

Antihypertensive drugs and brain function: mechanisms underlying therapeutically beneficial and harmful neuropsychiatric effects

A bidirectional relationship exists between hypertension and psychiatric disorders, including unipolar and bipolar depression, anxiety, post-traumatic stress disorder (PTSD), psychosis, schizophrenia, mania, and dementia/cognitive decline. Repurposing of antihypertensive drugs to treat mental disorders is thus being explored. A systematic knowledge of the mechanisms of action and clinical consequences of the use of antihypertensive agents on neuropsychiatric functions has not been achieved yet. In this article, we review the putative role of antihypertensive agents in psychiatric disorders, discuss the targets and mechanisms of action, and examine how and to what extent specific drug classes/molecules may trigger, worsen, or mitigate psychiatric symptoms. In addition, we review pharmacokinetics (brain penetration of drugs) and pharmacogenetics data that add important information to assess risks and benefits of antihypertensive drugs in neuropsychiatric settings. The scientific literature shows robust evidence of a positive effect of α1 blockers on PTSD symptoms, nightmares and sleep quality, α2 agonists on core symptoms, executive function and quality of life in Attention-Deficit/Hyperactivity Disorder, PTSD, Tourette's syndrome, and β blockers on anxiety, aggression, working memory, and social communication. Renin-angiotensin system modulators exert protective effects on cognition, depression, and anxiety, and the loop diuretic bumetanide reduced the core symptoms of autism in a subset of patients. There is no evidence of clear benefits of calcium channel blockers in mood disorders in the scientific literature. These findings are mainly from preclinical studies; clinical data are still insufficient or of anecdotal nature, and seldom systematic. The information herewith provided can support a better therapeutic approach to hypertension, tailored to patients with, or with high susceptibility to, psychiatric illness. It may prompt clinical studies exploring the potential benefit of antihypertensive drugs in selected patients with neuropsychiatric comorbidities that include outcomes of neuropsychiatric interest and specifically assess undesirable effects or interactions.

Sex Differences in Depression Caused by Early Life Stress and Related Mechanisms

Depression is a common psychiatric disease caused by various factors, manifesting with continuous low spirits, with its precise mechanism being unclear. Early life stress (ELS) is receiving more attention as a possible cause of depression. Many studies focused on the mechanisms underlying how ELS leads to changes in sex hormones, neurotransmitters, hypothalamic pituitary adrenocortical (HPA) axis function, and epigenetics. The adverse effects of ELS on adulthood are mainly dependent on the time window when stress occurs, sex and the developmental stage when evaluating the impacts. Therefore, with regard to the exact sex differences of adult depression, we found that ELS could lead to sex-differentiated depression through multiple mechanisms, including 5-HT, sex hormone, HPA axis, and epigenetics.

Serum Cortisol, Nesfatin-1, and IL-1β: Potential Diagnostic Biomarkers in Elderly Patients with Treatment-Resistant Depression

Aim

Treatment-resistant depression (TRD) affects approximately 30% of patients with major depressive disorder (MDD), especially elderly patients. As individuals with TRD are at an increased risk of committing suicide and pose a higher risk of relapse, early diagnostic biomarkers of TRD and a better understanding of the resistance mechanism are highly needed. This study aimed to determine whether serum cortisol, nesfatin-1, and pro-inflammatory cytokines can be used as biomarkers for the diagnosis of elderly patients with TRD.

Methods

Thirty elderly patients with TRD were selected as the TRD group. Thirty elderly patients with MDD who were effectively treated with conventional antidepressants were selected as the non-TRD group. The baseline levels of serum cortisol, nesfatin-1, and pro-inflammatory cytokines were measured and compared, and their diagnostic values were evaluated using the receiver operating characteristic (ROC) curve method for discriminating patients with TRD from those without TRD.

Results

Serum cortisol, C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) levels were significantly higher in the non-TRD and TRD groups than in the control group. Moreover, serum cortisol, CRP, TNF-α, and IL-6 levels in the TRD group were significantly lower than those in the non-TRD group. Furthermore, serum nesfatin-1 levels in the non-TRD group were significantly lower than those in the control and TRD groups, while the serum IL-1β levels in the non-TRD group were significantly higher than those in the control and TRD groups. Additionally, an ROC analysis revealed an area under the curve (AUC) of 0.929 for the combination of nesfatin-1 and IL-1β and an AUC of 0.956 for the combination of cortisol, nesfatin-1, and IL-1β in discriminating elderly patients with TRD from those without non-TRD.

Conclusion

Serum cortisol, nesfatin-1, and IL-1β may be potential diagnostic biomarkers for discriminating elderly patients with TRD from those without TRD.

Brain Mineralocorticoid receptor in health and disease: from molecular signaling to cognitive and emotional function

Brain mineralocorticoid receptors (MR) mediate effects of glucocorticoid hormones in stress adaptation, as well as the effects of aldosterone itself in relation to salt homeostasis. Brain stem MRs respond to aldosterone, whereas forebrain MRs mediate rapid and delayed glucocorticoid effects in conjunction with the glucocorticoid receptor (GR). MR‐mediated effects depend on age, gender, genetic variations, and environmental influences. Disturbed MR activity through chronic stress, certain (endocrine) diseases or during glucocorticoid therapy can cause deleterious effects on affective state, cognitive and behavioural function in susceptible individuals. Considering the important role MR plays in cognition and emotional function in health and disease, MR modulation by pharmacological intervention could relieve stress‐ and endocrine‐related symptoms. Here, we discuss recent pharmacological interventions in the clinic and genetic developments in the molecular underpinnings of MR signalling. Further understanding of MR‐dependent pathways may help to improve psychiatric symptoms in a diversity of settings.

A Delphi-method-based consensus guideline for definition of treatment-resistant depression for clinical trials

Criteria for treatment-resistant depression (TRD) and partially responsive depression (PRD) as subtypes of major depressive disorder (MDD) are not unequivocally defined. In the present document we used a Delphi-method-based consensus approach to define TRD and PRD and to serve as operational criteria for future clinical studies, especially if conducted for regulatory purposes. We reviewed the literature and brought together a group of international experts (including clinicians, academics, researchers, employees of pharmaceutical companies, regulatory bodies representatives, and one person with lived experience) to evaluate the state-of-the-art and main controversies regarding the current classification. We then provided recommendations on how to design clinical trials, and on how to guide research in unmet needs and knowledge gaps. This report will feed into one of the main objectives of the EUropean Patient-cEntric clinicAl tRial pLatforms, Innovative Medicines Initiative (EU-PEARL, IMI) MDD project, to design a protocol for platform trials of new medications for TRD/PRD.

Novel Pharmacological Approaches to the Treatment of Depression

Major depressive disorder is one of the most prevalent mental health disorders. Monoamine-based antidepressants were the first drugs developed to treat major depressive disorder. More recently, ketamine and other analogues were introduced as fast-acting antidepressants. Unfortunately, currently available therapeutics are inadequate; lack of efficacy, adverse effects, and risks leave patients with limited treatment options. Efforts are now focused on understanding the etiology of depression and identifying novel targets for pharmacological treatment. In this review, we discuss promising novel pharmacological targets for the treatment of major depressive disorder. Targeting receptors including N-methyl-D-aspartate receptors, peroxisome proliferator-activated receptors, G-protein-coupled receptor 39, metabotropic glutamate receptors, galanin and opioid receptors has potential antidepressant effects. Compounds targeting biological processes: inflammation, the hypothalamic-pituitary-adrenal axis, the cholesterol biosynthesis pathway, and gut microbiota have also shown therapeutic potential. Additionally, natural products including plants, herbs, and fatty acids improved depressive symptoms and behaviors. In this review, a brief history of clinically available antidepressants will be provided, with a primary focus on novel pharmaceutical approaches with promising antidepressant effects in preclinical and clinical studies.

Epigenetics: A missing link between early life stress and depression

Research has suggested a relationship between early life stress, and depression in particular longer episodes of depression with treatment resistant outcomes. However, the underlying mechanisms for this association remain poorly understood. Molecular studies indicate that, in general, the hereditary character of psychiatric disorders are polygenic, multifactorial and highly complex, with innumerable low-effect genetic variants interacting with each other. In addition, the importance of the environment and its interaction with genes has pointed to a fundamental role of epigenetic mechanisms in psychiatric disorders, such as methylation of deoxyribonucleic acid (DNA), alterations, histone actions and regulation of gene expression by non-coding ribonucleic acids (RNAs). This article provides an overview of the interplay of epigenetics, the HPA axis, early life stress and the development of depression. Advances in our knowledge of epigenetics in the context of early life stress and depression provide a new understanding of the genetic influence on psychopathology and could lead to the identification of new targets for clinical intervention.

High-dose spironolactone lacks effectiveness in treatment of fibromyalgia (RCT)

BACKGROUND

Spironolactone (SPL) is a reversible mineralocorticoid receptor (MR) and androgen receptor (AR) antagonist which attracts pharmacotherapeutic interest not only because of its beneficial effects in heart failure but also because of the pathogenetic roles of MR and AR activities in neuropsychiatric diseases. Recently, beneficial and rapid-onset effects of SPL have been documented in a case series of women with fibromyalgia syndrome (FMS). To reaffirm this observation, we performed a double-blind placebo-controlled randomized clinical trial (RCT).

METHODS

A total of 69 patients were screened, 56 patients were eligible and randomized to SPL or placebo (each n = 28). Forty-three patients completed the clinical trial to the last visit (n = 21 and n = 22). After a run-in phase of 50 and 100 mg/day, 200 mg/day SPL or placebo were applied between days 7 and 28. Primary outcome was the change in the FIQ-G score (Fibromyalgia Impact Questionnaire, German version). Secondary outcome parameters were the changes in pain (numeric rating scale, NRS), mood (ADS), quality of life (SF-36) and change in FIQ scores 14 days after the end of the medication.

RESULTS

SPL of 200 mg/day did not change significantly either the primary or the secondary end points. SPL evoked a transient rise in serum potassium and a transient fall in GFR maximal after 2 weeks, but without clinical relevance.

CONCLUSIONS

SPL at 200 mg/day does not improve symptoms in women with FMS, but was considered not to cause harm.

SIGNIFICANCE

The mineralocorticoid receptor and androgen receptor antagonist spironolactone is repeatedly tested for its therapeutic effectivity against neuropsychiatric disorders. The present RCT demonstrated that 200 mg spironolactone does not change the symptoms of the fibromyalgia syndrome (FMS) in adult women. Between 2 and 4 weeks, spironolactone evokes a transient decrease in GFR and increase in serum potassium. Spironolactone cannot be recommended for the treatment of FMS.

Comparison of hypothalamo-pituitary-adrenal function in treatment resistant unipolar and bipolar depression

Altered functioning of the hypothalamic-pituitary-adrenal (HPA) axis has been demonstrated in patients with treatment-resistant depression, although studies have often conflated patients with unipolar and bipolar depression. This is problematic given that the two groups often present with opposed neurovegetative symptom patterns. The aim of this study was to test, for the first time, whether post-awakening cortisol, a highly reliable, naturalistic measure of HPA functioning, could distinguish patients with clearly defined treatment-resistant unipolar (TRUD) and bipolar depression (TRBD). A total of 37 patients with TRUD, 17 patients with TRBD, and 47 healthy controls were recruited. Areas under the curve (AUC) with respect to the ground (g) and increase (i) of post-awakening cortisol concentrations (awakening, +15, +30, +45, +60, +90 min) were measured over two days. Patients with TRUD had higher total cortisol production in the morning hours compared to controls (AUCg, p = 0.01), while they did not differ in terms of the awakening response (AUCi, p = 0.28). By contrast, subjects with TRBD had lower total cortisol when compared to controls by trend (AUCg, p = 0.07), while they did not differ in the awakening response (AUCi, p = 0.15). A direct comparison of TRUD and TRBD revealed differences in the AUCg (p = 0.003) and AUCi (p = 0.03). This finding of comparatively elevated HPA axis activity in the morning in TRUD and attenuated HPA axis activity in TRBD attests to a fundamental biological distinction between unipolar and bipolar depression. It has implications for the understanding and treatment of bipolar depression and in differentiating the two types of depression.

Treatment-Resistant Depression Revisited: A Glimmer of Hope

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

Evaluation of the HPA Axis' Response to Pharmacological Challenges in Experimental and Clinical Early-Life Stress-Associated Depression

Early-life stress (ELS) is associated with a higher risk of psychopathologies in adulthood, such as depression, which may be related to persistent changes in the hypothalamic-pituitary-adrenal (HPA) axis. This study aimed to evaluate the effects of ELS on the functioning of the HPA axis in clinical and experimental situations. Clinically, patients with current depressive episodes, with and without ELS, and healthy controls, composed the sample. Subjects took a capsule containing placebo, fludrocortisone, prednisolone, dexamethasone or spironolactone followed by an assessment of plasma cortisol the morning after. Experimentally, male Wistar rats were submitted to ELS protocol based on variable, unpredictable stressors from postnatal day (PND)1 to PND21. On PND65 animals were behaviorally evaluated through the forced-swimming test (FST). At PND68, pharmacological challenges started, using mifepristone, dexamethasone, spironolactone, or fludrocortisone, and corticosterone levels were determined 3 h after injections. Cortisol response of the patients did not differ significantly from healthy subjects, regardless of their ELS history, and it was lower after fludrocortisone, prednisolone, and dexamethasone compared with placebo, indicating the suppression of plasma cortisol by all these treatments. Animals exposed to ELS presented altered phenotype as indicated by an increased immobility time in the FST when compared with control, but no significant long-lasting effects of ELS were observed on the HPA axis response. Limitations on the way the volunteers were sampled may have contributed to the lack of ELS effects on the HPA axis, pointing out the need for further research to understand these complex phenomena.

Neuroendocrine Stress System in Bipolar Disorder

Hormones have a crucial part in the progress and manifestation of a wide variety of different behaviors. The main influence of the neuroendocrine system on behavior is its action on the neurobiology of neuropsychiatric disorders and its relationship with the pharmacodynamics of medicines. Of all the neuroendocrine axes, the hypothalamic-pituitary-adrenal (HPA) axis has been the most extensively studied. There is evidence that disturbance in the HPA axis, the primary stress hormone system, could increase treatment resistance and relapse, worsen illness outcome, and cause cognitive deficits. Glucocorticoids mediate their actions in negative feedback binding in two different cytoplasmatic receptors described as mineralocorticoid receptors (MRs) and glucocorticoid receptors (GRs). Different psychopathologies underlying bipolar disorders are supposed to involve persistent dysfunctions in the expression and role of both MR and GR in the hippocampus. We review and analyze the evidence related to the correlation between bipolar disorders and the consequences and impact of stressful life events on the HPA axis, exploring the importance of these findings in bipolar disorders and as potential new targets for treatment.

The potential pathophysiological role of aldosterone and the mineralocorticoid receptor in anxiety and depression - Lessons from primary aldosteronism

High levels of aldosterone appear to be related to depressive and anxiety related behavior as demonstrated in therapy refractory depression and primary aldosteronism (PA). We analyzed data from a large register of patients with PA in order to clarify mediators and moderators of this influence. Up to 624 subjects were analyzed, however not all subjects had a complete dataset. Due to the known gender differences in subjects with PA we performed the analyses adjusted for gender. We compared subjects with (PHQ-9 ≥ 5) vs. no depressive symptomatology. 56% of men and 61% of women met this depression criterion. In women aldosterone concentration was significantly higher in depressed patients and renin levels were significantly increased with higher anxiety scores. This was not found in men. Depressive symptoms in men and women were significantly associated to BMI (men: dep vs non-dep: 29.6 vs. 28.4, p < 0.05; women: 26.9 vs. 24.5) and body weight (p < 0.05). Neither blood pressure nor electrolytes were different between depression groups. The relationship of these parameters to anxiety was less pronounced and partially unexpected: only in men higher anxiety (GAD ≥ 5) was related to lower systolic blood pressure. In conclusion, higher aldosterone appears to be associated with depressive symptoms in women, but less so in men with PA. BMI appears to be strongly and independently associated with depressive symptoms in patients with PA, independent of gender. Further studies are required to clarify the causal relationship.

Steroid hormone secretion after stimulation of mineralocorticoid and NMDA receptors and cardiovascular risk in patients with depression

Major depressive disorder (MDD) is associated with altered mineralocorticoid receptor (MR) and glucocorticoid receptor function, and disturbed glutamatergic signaling. Both systems are closely intertwined and likely contribute not only to the pathophysiology of MDD, but also to the increased cardiovascular risk in MDD patients. Less is known about other steroid hormones, such as aldosterone and DHEA-S, and how they affect the glutamatergic system and cardiovascular disease risk in MDD. We examined salivary cortisol, aldosterone, and DHEA-S secretion after stimulation of MR and glutamatergic NMDA receptors in 116 unmedicated depressed patients, and 116 age- and sex-matched healthy controls. Patients (mean age = 34.7 years, SD = ±13.3; 78% women) and controls were randomized to four conditions: (a) control condition (placebo), (b) MR stimulation (0.4 mg fludrocortisone), (c) NMDA stimulation (250 mg D-cycloserine (DCS)), and (d) combined MR/NMDA stimulation (fludrocortisone + DCS). We additionally determined the cardiovascular risk profile in both groups. DCS had no effect on steroid hormone secretion, while cortisol secretion decreased in both fludrocortisone conditions across groups. Independent of condition, MDD patients showed (1) increased cortisol, increased aldosterone, and decreased DHEA-S concentrations, and (2) increased glucose levels and decreased high-density lipoprotein cholesterol levels compared with controls. Depressed patients show profound alterations in several steroid hormone systems that are associated both with MDD pathophysiology and increased cardiovascular risk. Prospective studies should examine whether modulating steroid hormone levels might reduce psychopathology and cardiovascular risk in depressed patients.

Association of 11β-hydroxysteroid dehydrogenase type1 (HSD11b1) gene polymorphisms with outcome of antidepressant therapy and suicide attempts

The hypothalamic-pituitary-adrenal axis has been implicated in the pathophysiology of depressive disorders. HSD11B1 encodes 11β-hydroxysteroid dehydrogenase type1 enzyme, responsible for converting cortisone to cortisol. Genetic polymorphisms in HSD11B1 may impact in depression outcome and risk of suicide. This study aimed to assess whether HSD11B1 genotypes and haplotypes are associated with depression risk, severity of symptoms and suicidal attempts, considering early-life stress as an environmental factor. Here, 142 depressive patients and 103 healthy controls were included. Patients were enrolled from the Affective Disorders ambulatory and day hospital units, both within the University General Hospital of Ribeirao Preto. All subjects were clinically assessed applying the Mini-PLUS International Neuropsychiatric Interview, followed by the 21-item GRID-Hamilton Depression Scale, Childhood Trauma Questionnaire and Beck Scale for Suicidal Ideation (BSI). All subjects underwent antecubital vein puncture to obtain blood for DNA extraction. Genotyping of rs11119328 and rs11811440 were performed using allele-specific oligonucleotide polymerase chain reaction. We found a significant association of rs11119328 variant genotypes with increased risk for at least one suicide attempt (OR: 7.10, p = 0.049) and an association of variant genotypes of rs11811440 with euthymic mood under optimized pharmacological treatment (OR: 0.05, P = 0.014). These tests included correction for confounding factors. The association of genetic markers with depression risk, GRID-HAM-D₂₁ and BSI scores and the number of suicidal attempts were nonsignificant. Haplotypes combining both markers were not associated with the studied phenotypes. We conclude that HSD11B1 polymorphisms may be relevant biomarkers for detecting subjects genetically vulnerable to poorer antidepressant response and higher risk of suicide attempts.

Adjunct Therapy With Glycyrrhiza Glabra Rapidly Improves Outcome in Depression-A Pilot Study to Support 11-Beta-Hydroxysteroid Dehydrogenase Type 2 Inhibition as a New Target

Mineralocorticoid-receptor (MR) dysfunction as expressed by low systolic blood pressure and a high salivary aldosterone/cortisol ratio predicts less favorable antidepressant treatment outcome. Inhibition of peripheral 11-beta-hydroxysteroid-dehydrogenase type 2 (11betaHSD2) reverses these markers. We therefore tested the hypothesis that the 11betaHSD2 inhibitor glycyrrhizin affects treatment outcome via this mechanism. We administered Glycyrrhiza glabra (GG) extract containing 7-8 % of glycyrrhizin at a dose of 2 × 700 mg daily adjunct to standard antidepressants in hospitalized patients with major depression. These subjects were compared in an open-label fashion with patients, who did not receive GG (treatment as usual, TAU). Assessments were done at baseline and approximately 2 weeks after. Twelve subjects were treated with GG and compared to 55 subjects with TAU. At week 2, the Hamilton Depression Rating Scale (HAMD-21) change from baseline as well as the CGI-S change showed a significant time × treatment interaction (p < 0.03), indicating a possible therapeutic benefit of GG. Clinical benefit seems to be more pronounced in subjects with lower systolic blood pressure and significantly correlated with reduced sleep duration in the GG group. Our preliminary data show that treatment with the 11betaHSD2 inhibitor glycyrrhizin may possess a beneficial effect on antidepressant response, which may be specific to a defined depression subtype.

Baseline cortisol and the efficacy of antiglucocorticoid treatment in mood disorders: A meta-analysis

INTRODUCTION

Hyperactivity of the Hypothalamic-Pituitary-Adrenal (HPA) axis and high cortisol levels have been widely reported in patients with mood disorders but previous clinical trials investigating the efficacy of antiglucocorticoid treatment in this population have reported inconsistent findings. The inconsistencies among these studies may be because not all patients with mood disorders have increased HPA axis activity and therefore might not benefit from antiglucocorticoid treatment. The aim of this meta-analysis was to investigate whether baseline cortisol levels influence the efficacy of antiglucocorticoid drugs in patients with mood disorders.

METHODS

PubMed and Scopus databases were searched systematically up to October 2018. We included studies using metyrapone, ketoconazole or mifepristone in patients with major depressive disorder, bipolar disorder and major depressive disorder with psychotic symptoms. We tested for a difference in cortisol levels between responders (a reduction equal to or greater than 30% on depression scales following antiglucocorticoid treatment) and non-responders (a reduction of less than 30% on depression scales). We performed a meta-analysis to look specifically at differences in cortisol levels in the sample of patients treated with cortisol synthesis inhibitors (metyrapone and ketoconazole) and in those treated with glucocorticoid receptor (GR) antagonist (mifepristone).

RESULTS

We were able to retrieve data from 11 of the 16 selected studies and to include 9 studies in the meta-analysis. In the overall sample (N = 846), responders had similar baseline cortisol levels compared with non-responders (standardised mean difference, SMD = -0.03, 95% CI [-0.17, 0.12], p = 0.75). In the group of patients treated with cortisol synthesis inhibitors, responders (N = 109) had significantly higher peripheral baseline cortisol levels compared with non-responders (SMD = 0.42, 95% CI [0.01, 0.83], p = 0.047). In the group of patients treated with a GR antagonist (N = 737), both responders and non-responders had similar baseline cortisol levels (SMD = -0.09, 95% CI [-0.25, 0.07], p = 0.26).

CONCLUSION

Our data suggest that only patients with higher cortisol levels at baseline benefit from treatment with cortisol synthesis inhibitors and support a potential role for cortisol as a predictive biomarker for treatment with cortisol synthesis inhibitors in patients with mood disorders.

Sex differences in the hypothalamic-pituitary-adrenal axis: An obstacle to antidepressant drug development?

Hypothalamic-pituitary-adrenal (HPA) axis dysfunction has long been implicated in the pathophysiology of depression, and HPA axis-based compounds have served as potential new therapeutic targets, but with no success. This review details sex differences from animal and human studies in the function of HPA axis elements (glucocorticoids, corticotropin releasing factor, and vasopressin) and related compounds tested as candidate antidepressants. We propose that sex differences contribute to the failure of novel HPA axis-based drugs in clinical trials. Compounds studied preclinically in males were tested in clinical trials that recruited more, if not exclusively, women, and did not control, but rather adjusted, for potential sex differences. Indeed, clinical trials of antidepressants are usually not stratified by sex or other important factors, although preclinical and epidemiological data support such stratification. In conclusion, we suggest that clinical testing of HPA axis-related compounds creates an opportunity for targeted, personalized antidepressant treatments based on sex. LINKED ARTICLES: This article is part of a themed section on The Importance of Sex Differences in Pharmacology Research. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.21/issuetoc.

Mineralocorticoid receptor function and cognition in health and disease

The steroid hormone cortisol is released in response to stress and exerts its effects in the brain via two different receptors: the mineralocorticoid receptor (MR) and the glucocorticoid receptor (GR). This review - dedicated to Dirk Hellhammer - focusses on the role of MR on cognitive and emotional function in healthy individuals and in stress-associated disorders such as major depressive disorder (MDD) or borderline personality disorder (BPD). Animal data and studies from healthy individuals converge such that MR play an important role in the appraisal of new situations and the following response selection. Decision-making and empathy are important determinants of this response selection and both are affected by MR function. Furthermore, MR are crucially involved in visuospatial navigation and memory in young and elderly healthy individuals whereas the exact physiological role of MR in verbal learning and verbal memory needs to be further characterized. In contrast to studies in healthy participants, age played a moderating role on the effects of MR stimulation on cognition in depressed patients. In young depressed patients, MR stimulation exerted beneficial effects on verbal memory and executive function, whereas in elderly depressed patients MR stimulation led to impaired verbal learning and visuospatial memory. Similar to healthy controls, BPD patients showed enhanced emotional empathy but not cognitive empathy after MR stimulation. Accordingly, this make MR an interesting target for potential pharmacological augmentation of psychotherapy in BPD. Given the important role MR play in cognitive and emotional function in health and disease, further studies should examine whether MR modulation can alleviate cognitive and emotional problems in patients with stress-associated disorders.

Altered cellular immune reactivity in traumatized women with and without major depressive disorder

Alterations of the hypothalamic-pituitary-adrenal (HPA) axis such as altered glucocorticoid receptor sensitivity and increased immune reactivity might contribute to the pathogenesis of major depressive disorder (MDD). Exposure to adverse childhood experiences (ACE) precipitates vulnerability to MDD and might be associated with endocrine and immune alterations in the disorder. In order to disentangle the effects of ACE and MDD, we recruited 87 women: n = 23 with MDD and ACE as determined by clinical interview and questionnaires (Structured Clinical Interview for DSM-IV, Early Trauma Inventory, Childhood Trauma Questionnaire), n = 24 with MDD without ACE, n = 21 with ACE but no current or lifetime MDD, and n = 26 healthy women without either MDD or ACE. Glucocorticoid signaling and mitogen-stimulated proliferation were analyzed ex vivo in peripheral blood-derived mononuclear cells. Additionally, mRNA expression of the glucocorticoid and the mineralocorticoid receptor (GR / MR) was assessed. Peripheral GR sensitivity as well as GR and MR expression levels were not significantly different between groups. Women with ACE showed an increased immune response after mitogen stimulation independent of the presence of MDD. Our results provide evidence for a functionally altered ex-vivo immune response in cell cultures from women with a history of ACE. Thus, ACE might contribute to the pathogenesis of MDD through inflammatory pathways.

Correlation of clinical features with hs-CRP in TRD patients

Correlation of clinical features with hypersensitive C-reactive protein (hs-CRP) in patients with treatment-resistant depression (TRD) was investigated. The severity of disease in 103 TRD patients and 103 non-TRD patients was evaluated using the Hamilton Depression Scale (HAMD)-17. The levels of hs-CRP in both groups were detected via immunofluorescence. Clinical features and differences in hs-CRP before and after treatment in both groups were analyzed, and correlation of baseline hs-CRP level with clinical features of TRD patients was also analyzed. Moreover, the relationship between hs-CRP and occurrence of TRD was analyzed using logistic regression analysis, and the diagnostic value of hs-CRP in TRD was evaluated using the receiver operating characteristic (ROC) curve. The onset age in the TRD group was lower than that in the non-TRD group, the education in the TRD group was shorter than that in the non-TRD group, the total course of disease in the TRD group was longer than that in the non-TRD group, and both baseline and post-treatment hs-CRP level in the TRD group (12.05±5.79 and 9.02±3.71 mg/l) were higher than those in the non-TRD group (7.85±2.85 and 6.10±2.74 mg/l) (p<0.05). The HAMD score (r=0.338, p=0.031), anxiety/somatization factor score (r=0.465, p=0.015) and sleep disorder (r=0.387, p=0.029) of TRD patients were positively correlated with the hs-CRP level, but the onset age (r=−0.59, p=0.009) was negatively correlated with the hs-CRP level. Logistic regression analysis revealed that the baseline hs-CRP was included into the TRD regression equation [odds ratio (OR) =2.834, 95% confidence interval (CI) =1.723–4.886], and the area under the ROC curve was 0.893 (p<0.05, 95% CI=0.852–0.933). In the TRD group, the course of TRD in patients was longer, the onset of disease was earlier and the educational level was lower than that in the non-TRD group. Therefore, the level of hs-CRP can serve as a reference for the diagnosis of TRD.

International Union of Basic and Clinical Pharmacology CIV: The Neurobiology of Treatment-resistant Depression: From Antidepressant Classifications to Novel Pharmacological Targets

Major depressive disorder is one of the most prevalent and life-threatening forms of mental illnesses and a major cause of morbidity worldwide. Currently available antidepressants are effective for most patients, although around 30% are considered treatment resistant (TRD), a condition that is associated with a significant impairment of cognitive function and poor quality of life. In this respect, the identification of the molecular mechanisms contributing to TRD represents an essential step for the design of novel and more efficacious drugs able to modify the clinical course of this disorder and increase remission rates in clinical practice. New insights into the neurobiology of TRD have shed light on the role of a number of different mechanisms, including the glutamatergic system, immune/inflammatory systems, neurotrophin function, and epigenetics. Advances in drug discovery processes in TRD have also influenced the classification of antidepressant drugs and novel classifications are available, such as the neuroscience-based nomenclature that can incorporate such advances in drug development for TRD. This review aims to provide an up-to-date description of key mechanisms in TRD and describe current therapeutic strategies for TRD before examining novel approaches that may ultimately address important neurobiological mechanisms not targeted by currently available antidepressants. All in all, we suggest that drug targeting different neurobiological systems should be able to restore normal function but must also promote resilience to reduce the long-term vulnerability to recurrent depressive episodes.

Hormonal Treatment of Transgender Women with Oral Estradiol

Purpose: Maintaining cross-sex hormone levels in the normal physiologic range for the desired gender is the cornerstone of transgender hormonal therapy, but there are limited data on how to achieve this. We investigated the effectiveness of oral estradiol therapy in achieving this goal.

Methods: We analyzed data on all transgender females seen in our clinic since 2008 treated with oral estradiol. We looked at the success of achieving serum levels of testosterone and 17-β estradiol in the normal range on various doses of estradiol (with and without antiandrogens spironolactone and finasteride).

Results: There was a positive correlation between estradiol dose and 17-β estradiol, but testosterone suppression was less well correlated. Over 70% achieved treatment goals (adequate 17-β estradiol levels and testosterone suppression) on 4 mg daily or more. Nearly a third of patients did not achieve adequate treatment goals on 6 or even 8 mg daily of estradiol. Spironolactone, but not finasteride, use was associated with impairment of obtaining desired 17-β estradiol levels. Spironolactone did not enhance testosterone suppression, and finasteride was associated with higher testosterone levels.

Conclusions: Oral estradiol was effective in achieving desired serum levels of 17-β estradiol, but there was wide individual variability in the amount required. Oral estradiol alone was not infrequently unable to achieve adequate testosterone suppression. Spironolactone did not aid testosterone suppression and seemed to impair achievement of goal serum 17-β estradiol levels. Testosterone levels were higher with finasteride use. We recommend that transgender women receiving estradiol therapy have hormone levels monitored so that therapy can be individualized.

Mineralocorticoid receptor function in depressed patients and healthy individuals

BACKGROUND

Many studies have shown disturbed glucocorticoid receptor (GR) in depressed patients. In contrast, only few studies targeted mineralocorticoid receptor (MR) function with inconclusive results. We examined the effects of the MR antagonist spironolactone on cortisol secretion in depressed patients and healthy individuals.

METHODS

Forty-eight unmedicated depressed patients (mean age 41.6years) and 45 age- and sex-matched healthy participants (40.7years) received the MR antagonist spironolactone (300mg) or placebo with three days apart in a randomized, double-blind, within-subject cross-over design. We measured salivary cortisol before ingestion of study medication (baseline) as well as +60min, +90min, +120min, +150min and 180min after baseline.

RESULTS

Repeated-measures ANOVA for area under the curve (AUCg) cortisol revealed a treatment effect with higher cortisol after spironolactone and a treatment by group interaction. Post-hoc analyses revealed higher cortisol in depressed patients compared to healthy participants in the placebo condition. In the spironolactone condition, the cortisol levels were not significantly different.

CONCLUSIONS

Potentially, impaired MR or GR signaling could be responsible for higher cortisol levels in depressed patients in the placebo condition. However, after MR blockade that increased cortisol secretion across groups leading to higher GR occupation, we found no differences between depressed patients and healthy controls. Thus, our results argue for depression-associated alterations in MR signaling rather than disturbed GR-mediated feedback inhibition.

Stress and Depression: a Crucial Role of the Mineralocorticoid Receptor

Cortisol and corticosterone act on the appraisal process, which comprises the selection of an appropriate coping style and the encoding of the experience for storage in the memory. This action exerted by the stress hormones is mediated by mineralocorticoid receptors (MRs), which are expressed abundantly in the limbic circuitry, particularly in the hippocampus. Limbic MR is down-regulated by chronic stress and during depression but induced by antidepressants. Increased MR activity inhibits hypothalamic-pituitary-adrenal axis activity, promotes slow wave sleep, reduces anxiety and switches circuit connectivity to support coping. Cortisol and emotion-cognition are affected by MR gene haplotypes based on rs5522 and rs2070951. Haplotype 1 (GA) moderates the effects of (early) life stressors, reproductive cycle and oral contraceptives. MR haplotype 2 (CA) is a gain of function variant that protects females against depression by association with an optimistic, resilient phenotype. Activation of MR therefore may offer a target for alleviating depression and cognitive dysfunction. Accordingly, the MR agonist fludrocortisone was found to enhance the efficacy of antidepressants and to improve memory and executive functions in young depressed patients. In conclusion, CORT coordinates via MR the networks underlying how an individual copes with stress, and this action is complemented by the widely distributed lower affinity glucocorticoid receptor (GR) involved in the subsequent management of stress adaptation. In this MR:GR regulation, the MR is an important target for promoting resilience.

Rhodiola rosea L. as a putative botanical antidepressant

BACKGROUND

Rhodiola rosea (R. rosea) is a botanical adaptogen with putative anti-stress and antidepressant properties. Evidence-based data supporting the effectiveness of R. rosea for depression in adults is limited, and therefore a comprehensive review of available animal and human studies suggesting a putative antidepressant action is warranted.

PURPOSE

A review of the literature was undertaken to ascertain studies of possible antidepressant mechanisms of action and studies of the safety and effectiveness of R. rosea extracts in animals and adult humans.

METHODS

A search of MEDLINE and the Russian state library database was conducted (up to October 2015) on R. rosea.

MECHANISM OF ACTION

R. rosea extracts and its purified constituent, salidroside, has been shown to produce a variety of mediator interactions with several molecular networks of neuroendocrine-immune and neurotransmitter receptor systems likely to be involved in the pathophysiology of depression. A wide variety of preclinical in vivo and ex vivo studies with laboratory animals suggests the presence of several biochemical and pharmacological antidepressant-like actions.

EFFECTIVENESS

Clinical assessment of R. rosea L. rhizome extracts in humans with various depressive syndromes is based upon results from two randomized, double-blind, placebo-controlled trials of 146 subjects with major depressive disorder and seven open-label studies totaling 714 individuals with stress-induced mild depression (diagnosed as asthenic syndrome or psychoneurosis). Overall, results of these studies suggests a possible antidepressant action for R. rosea extract in adult humans.

SAFETY

In contrast to most conventional antidepressants, R. rosea extract appears to be well-tolerated in short-term studies with a favorable safety profile.

CONCLUSIONS

R. rosea demonstrates multi-target effects on various levels of the regulation of cell response to stress, affecting various components of the neuroendocrine, neurotransmitter receptor and molecular networks associated with possible beneficial effects on mood.

Cognitive function in older adults with major depression: Effects of mineralocorticoid receptor stimulation

Memory and executive function are often impaired in older adults with major depression. Mineralocorticoid receptors (MR) are abundantly expressed in the hippocampus and in the prefrontal cortex, brain areas critical for memory and executive function. In both aging and depression, MR expression in the brain is reduced. Therefore, diminished MR function could contribute to impaired cognition in older adults with depression and might be a promising target for pharmacological intervention. Twenty-three older adults with major depression (mean age 61.6 yrs ± 8.1, n = 13 women) without medication and 24 age-, sex- and education-matched healthy participants received the MR-agonist fludrocortisone (0.4 mg) or placebo in a randomized, double-blind, within-subject cross-over design. We measured psychomotor speed, executive function, verbal learning and memory, and visuospatial memory. Compared to controls, depressed patients performed worse in psychomotor speed (group effect p = 0.01), executive function (group effect p < 0.01), verbal learning (group effect p = 0.02), and verbal memory (group effect p < 0.01) but not in visuospatial memory. There were no significant treatment effects. However, we found a group × treatment interaction in verbal learning (p = 0.04) and visuospatial memory (p = 0.02) indicating that depressed patients performed worse after fludrocortisone whereas controls performed better after fludrocortisone. Our data suggest that -in contrast to younger depressed patients-older adults with depression do not benefit from MR stimulation but deteriorate in cognitive function.

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

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

Target-based biomarker selection - Mineralocorticoid receptor-related biomarkers and treatment outcome in major depression

Aldosterone and mineralocorticoid receptor (MR)-function have been related to depression. We examined central and peripheral parameters of MR-function in order to characterize their relationship to clinical treatment outcome after six weeks in patients with acute depression. 30 patients with a diagnosis of major depression were examined 3 times over a 6 week period. Aldosterone and cortisol salvia samples were taken at 7.00 a.m. before patients got out of bed. Easy to use e-devices were used to measure markers of central MR function, i.e. slow wave sleep (SWS) and heart-rate variability (HRV). Salt-taste intensity (STI) and salt pleasantness (SP) of a 0.9% salt solution were determined by a newly developed scale. In addition, systolic blood pressure (SBP) and plasma electrolytes were determined as markers for peripheral MR activity. The relationship between the levels of these biomarkers at baseline and the change in clinical outcome parameters (Hamilton depression rating scale (HDRS)-21, anxiety, QIDS and BDI) after 6 weeks of treatment was investigated. A higher aldosterone/cortisol ratio (Aldo/Cort) (n = 17 due to missing values; p < 0.05) and lower SBP (n = 24; p < 0.05) at baseline predicted poor outcome, as measured with the HDRS, independent of gender. Only in male patients higher STI, lower SP, lower SWS (all n = 13) and higher HRV (n = 11) at baseline predicted good outcome p < 0.05). Likewise, in male patients low baseline sodium appears to be predictive for a poor outcome (n = 12; p = 0.05; based on HDRS-6). In conclusion, correlates of higher central MR-activation are associated with poorer clinical improvement, particularly in men. This contrasts with the finding of a peripheral MR-desensitization in more refractory patients. As one potential mechanism to consider, sodium loss on the basis of dysfunctional peripheral MR function and additional environmental factors may trigger increased aldosterone secretion and consequently worse outcome. These markers deserve further study as potential biological correlates for therapy refractory depression.

The brain mineralocorticoid receptor and stress resilience

Stress exposure activates the HPA-axis and results in the release of corticosteroids which bind to two receptor types in the brain: the mineralocorticoid receptor (MR) and the glucocorticoid receptor (GR). While the role of the GR in stress reactivity has been extensively studied, the MR has received less attention. Nevertheless, pioneering in-depth studies over the past two decades have shown the importance of the brain MR in the processing of stressful information. Moreover, a membrane-bound MR mediating the rapid effects of cortisol was recently discovered. This review summarizes how the MR may play a role in stress resilience. Both preclinical and clinical studies suggest that the MR is an important stress modulator and influences basal as well as stress-induced HPA-axis activity, stress appraisal, and fear-related memories. These MR effects are mediated by both genomic and non-genomic MRs and appear to be at least partially sex-dependent. Moreover, the majority of studies indicate that high MR functionality or expression may confer resilience to traumatic stress. This has direct clinical implications. First, increasing activity or expression of brain MRs may prevent or reverse symptoms of stress-related depression. Second, individuals with a relatively low MR functionality may possess an increased stress susceptibility for depression. Nevertheless, the number of clinical MR studies is currently limited. In conclusion, the recent emergence of the MR as a putative stress resilience factor is important and may open up new avenues for the prevention and treatment of psychiatric disorders.

Mineralocorticoid receptor stimulation improves cognitive function and decreases cortisol secretion in depressed patients and healthy individuals

Memory and executive function are often impaired in patients with major depression, while cortisol secretion is increased. Mineralocorticoid receptors (MR) are abundantly expressed in the hippocampus and in the prefrontal cortex, brain areas critical for memory, executive function, and cortisol inhibition. Here, we investigated whether MR stimulation with fludrocortisone (1) improves memory and executive function and (2) decreases cortisol secretion in depressed patients and healthy individuals. Twenty-four depressed patients without medication and 24 age-, sex-, and education-matched healthy participants received fludrocortisone (0.4 mg) or placebo in a randomized, double-blind, within-subject cross-over design. We measured verbal memory, visuospatial memory, executive function, psychomotor speed, and salivary cortisol secretion during cognitive testing between 1400 and 1700 hours. For verbal memory and executive function, we found better performance after fludrocortisone compared with placebo across groups. No treatment effect on other cognitive domains emerged. Depressed patients performed worse than healthy individuals in psychomotor speed and executive function. No group effect or group × treatment interaction emerged on other cognitive domains. Fludrocortisone decreased cortisol secretion across groups and there was a significant correlation between cortisol inhibition and verbal memory performance. Our data suggest a crucial role of MR in verbal memory and executive function and demonstrate the possibility to improve cognition in depressed patients and healthy individuals through MR stimulation.

The association of post-stroke anhedonia with salivary cortisol levels and stroke lesion in hippocampal/parahippocampal region

BACKGROUND

Anhedonia constitutes a coherent construct, with neural correlates and negative clinical impact, independent of depression. However, little is known about the neural correlates of anhedonia in stroke patients. In this study, we investigated the association of post-stroke anhedonia with salivary cortisol levels and stroke location and volume.

PATIENTS AND METHODS

A psychiatrist administered the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition to identify anhedonia in 36 inpatients, without previous depression, consecutively admitted in a neurology clinic in the first month after a first-ever ischemic stroke. Salivary cortisol levels were assessed in the morning, evening, and after a dexamethasone suppression test. We used magnetic resonance imaging and a semi-automated brain morphometry method to assess stroke location, and the MRIcro program according to the Brodmann Map to calculate the lesion volume.

RESULTS

Patients with anhedonia had significantly larger diurnal variation (P-value =0.017) and higher morning levels of salivary cortisol (1,671.9±604.0 ng/dL versus 1,103.9±821.9 ng/dL; P-value =0.022), and greater stroke lesions in the parahippocampal gyrus (Brodmann area 36) compared to those without anhedonia (10.14 voxels; standard deviation ±17.72 versus 0.86 voxels; standard deviation ±4.64; P-value =0.027). The volume of lesion in the parahippocampal gyrus (Brodmann area 36) was associated with diurnal variation of salivary cortisol levels (rho=0.845; P-value =0.034) only in anhedonic patients.

CONCLUSION

Our findings suggest that anhedonia in stroke patients is associated with the volume of stroke lesion in the parahippocampal gyrus and with dysfunction of the hypothalamic-pituitary-adrenal axis.

Early-life stress and HPA axis trigger recurrent adulthood depression

It is now broadly accepted that psychological stress may change the internal homeostatic state of an individual. During acute stress, adaptive physiological responses occur, which include hyperactivity of the HPA axis. Whenever there is an acute interruption of this balance, illness may result. The social and physical environments have an enormous impact on our physiology and behavior, and they influence the process of adaptation or 'allostasis'. It is correct to state that at the same time that our experiences change our brain and thoughts, namely, changing our mind, we are changing our neurobiology. Increased adrenocortical secretion of hormones, primarily cortisol in major depression, is one of the most consistent findings in neuropsychiatry. A significant percentage of patients with major depression have been shown to exhibit increased concentrations of cortisol, an exaggerated cortisol response to adrenocorticotropic hormone, and an enlargement of both the pituitary and adrenal glands. The maintenance of the internal homeostatic state of an individual is proposed to be based on the ability of circulating glucocorticoids to exert negative feedback on the secretion of hypothalamic-pituitary-adrenal (HPA) hormones through binding to mineralocorticoid (MR) and glucocorticoid (GR) receptors limiting the vulnerability to diseases related to psychological stress in genetically predisposed individuals. The HPA axis response to stress can be thought of as a mirror of the organism's response to stress: acute responses are generally adaptive, but excessive or prolonged responses can lead to deleterious effects. Evidence indicates that early-life stress can induce persistent changes in the ability of the HPA axis to respond to stress in adulthood. These abnormalities appear to be related to changes in the ability of hormones to bind to GR and MR receptors. First episodes may begin with an environmental stressor, but if the cycles continue or occur unchecked, the brain becomes kindled or sensitized, and future episodes of depression, hypomania, or mania will occur independently of an outside stimulus, with greater frequency and intensity. Generally, HPA axis changes appear in chronic depressive and more severe episodes. Moreover, HPA axis changes appear to be state-dependent, tending to improve upon resolution of the depressive syndrome. Interestingly, persistent HPA dysfunction has been associated with higher rates of relapse and chronicity.

HPA axis and aging in depression: systematic review and meta-analysis

One of the most consistent findings in the biology of depression is an altered activity of the hypothalamic-pituitary-adrenal (HPA) axis. However, data concerning this issue have never been examined with a focus on the older population. Here we present a systematic review and meta-analysis, based on studies investigating levels of cortisol, adrenocorticotropic hormone (ACTH) and corticotropin-releasing hormone (CRH) in depressed participants older than 60 and compared with healthy controls. We found 20 studies, for a total of 43 comparisons on different indices of HPA axis functioning. Depression had a significant effect (Hedges' g) on basal cortisol levels measured in the morning (0.89), afternoon (0.83) and night (1.39), but a smaller effect on cortisol measured continuously (0.51). The effect of depression was even higher on post-dexamethasone cortisol levels (3.22), whereas it was non-significant on morning ACTH and CRH levels. Subgroup analyses indicated that various methodological and clinical factors can influence the study results. Overall, older participants suffering from depression show a high degree of dysregulation of HPA axis activity, with differences compared with younger adults. This might depend on several mechanisms, including physical illnesses, alterations in the CNS and immune-endocrinological alterations. Further studies are needed to clarify the implications of altered HPA axis activity in older patients suffering from depression. Novel pharmacological approaches might be effective in targeting this pathophysiological feature, thus improving the clinical outcomes.

Early Life Stress in Depressive Patients: HPA Axis Response to GR and MR Agonist

BACKGROUND

Evidence indicates that early life stress (ELS) can induce persistent changes in the hypothalamic-pituitary-adrenal (HPA) axis to respond to stress in the adult life that leads to depression. These appear to be related to the impairment of HPA hormones through binding to glucocorticoid (GR) and mineralocorticoid receptors (MR). The aim of this study was to evaluate the impact of ELS in HPA axis response to challenges with GR and MR agonists in depressed patients.

METHODS

We included 30 subjects, 20 patients with current major depression (HAM-D21 ≥ 17). Patients were recruited into two groups according to ELS history assessed by the Childhood Trauma Questionnaire (CTQ). The cortisol measures in the saliva and plasma were evaluated after using (at 10:00 p.m.) placebo, fludrocortisone (MR agonist), or dexamethasone (GR agonist).

RESULTS

Depressed patients showed a significantly lower salivary cortisol upon waking after placebo compared with controls. Moreover, cortisol awakening responses (CAR) after MR agonist were found to be lower in depressed patients than in controls. With CTQ scores, HAM-D21, body mass index and CAR after placebo, GR agonist, MR agonist we found in a Linear Regression model that depressive patients with ELS (p = 0.028) show differences between placebo vs. MR agonist (R = 0.51; p < 0.05) but not after GR agonist; in depressive patients, without ELS the data show differences between placebo vs. MR agonist (R = 0.69; p < 0.05); but now as well placebo vs. GR agonist (R = 0.53; p < 0.05).

CONCLUSION

Our findings indicate that MR activity is impaired in depressed patients compared with controls. Furthermore, in spite of the previous limitations described, in depressed patients with ELS, there was suppression by MR agonist, indicating that patients with ELS are sensitive to MR agonists. In contrast with depressed patients without ELS, we find suppression after both MR and GR agonist. These data suggested that in ELS an imbalance exists between MR and GR with MR dysfunction.