Combined dexamethasone suppression-corticotrophin-releasing hormone stimulation test in medication-free major depression and healthy volunteers

The neurodegenerative hypothesis of depression and the influence of antidepressant medications

Depression is a complex neurological disease that holds many theories on its aetiology and pathophysiology. The monoamine strategy of treating depression with medications to increase levels of monoamines in the (extra)synapse, primarily through the inhibition of monoamine transporters, does not always work, as seen in patients that lack a response to multiple anti-depressant exposures, as well as a lack of depressive symptoms in healthy volunteers exposed to monoamine reduction. Depression is increasingly being understood not as a single condition, but as a complex interplay of adaptations in various systems, including inflammatory responses and neurotransmission pathways in the brain. This understanding has led to the development of the neurodegenerative hypothesis of depression. This hypothesis, which is gaining widespread acceptance posits that both oxidative stress and inflammation play significant roles in the pathophysiology of depression. This article is a review of the literature focused on neuroinflammation in depression, as well as summarised studies of anti-inflammatory and antioxidant effects of antidepressants.

The dexamethasone suppression test as a biomarker for suicidal behavior: A systematic review and meta-analysis

BACKGROUND

The dexamethasone suppression test (DST), which measures HPA-axis functioning, is a potential biomarker for suicidal behavior. The current study aimed (a) to synthesize available knowledge on the association between DST non-suppression and suicidal behavior, and (b) to study potential moderators.

METHODS

A total of 4236 studies were screened, 43 were included. Suicide attempts and suicide completion were studied separately. The meta-analysis included 37 effect sizes for suicide attempts (n = 3733) and 11 effect sizes for suicide completion (n = 1626).

RESULTS

DST non-suppression was associated with completed suicide (odds ratio (OR) = 2.10, (95 % CI [1.37, 3.23]). For suicide attempts, we found no evidence that DST status was associated in the overall meta-analysis including all patient samples. However, moderator analysis indicated that the DST status was associated with suicide attempts in patient samples that included psychopathology other than just mood disorders, such as psychotic, substance use and personality disorders (OR = 2.34, 95 % CI [1.39-3.93], k = 11).

LIMITATIONS

The potential influence of publication bias and exclusion of some relevant published studies (since effect sizes could not be calculated, authors could not supply data or authors could not be reached) are limitations. Furthermore, missing moderator data decreased our ability to explain heterogeneity between studies.

CONCLUSIONS

The results of this meta-analysis support the hypothesis that DST non-suppression is predictive of suicidal behavior. More research is needed to investigate optimal cut-off values, confounding factors and the potential usefulness of the DST in clinical practice in terms of personalized medicine.

Dissecting the Relationship Between Neuropsychiatric and Neurodegenerative Disorders

Neurodegenerative diseases (NDDs) and neuropsychiatric disorders (NPDs) are two common causes of death in elderly people, which includes progressive neuronal cell death and behavioral changes. NDDs include Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, multiple sclerosis, and motor neuron disease, characterized by cognitive defects and memory impairment, whereas NPDs include depression, seizures, migraine headaches, eating disorders, addictions, palsies, major depressive disorders, anxiety, and schizophrenia, characterized by behavioral changes. Mounting evidence demonstrated that NDDs and NPDs share an overlapping mechanism, which includes post-translational modifications, the microbiota-gut-brain axis, and signaling events. Mounting evidence demonstrated that various drug molecules, namely, natural compounds, repurposed drugs, multitarget directed ligands, and RNAs, have been potentially implemented as therapeutic agents against NDDs and NPDs. Herein, we highlighted the overlapping mechanism, the role of anxiety/stress-releasing factors, cytosol-to-nucleus signaling, and the microbiota-gut-brain axis in the pathophysiology of NDDs and NPDs. We summarize the therapeutic application of natural compounds, repurposed drugs, and multitarget-directed ligands as therapeutic agents. Lastly, we briefly described the application of RNA interferences as therapeutic agents in the pathogenesis of NDDs and NPDs. Neurodegenerative diseases and neuropsychiatric diseases both share a common signaling molecule and molecular phenomenon, namely, pro-inflammatory cytokines, γCaMKII and MAPK/ERK, chemokine receptors, BBB permeability, and the gut-microbiota-brain axis. Studies have demonstrated that any alterations in the signaling mentioned above molecules and molecular phenomena lead to the pathophysiology of neurodegenerative diseases, namely, Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis, and neuropsychiatric disorders, such as bipolar disorder, schizophrenia, depression, anxiety, autism spectrum disorder, and post-traumatic stress disorder.

Testosterone Replacement Therapy in the Treatment of Depression

BACKGROUND

Depression is a common disorder that affects millions globally and is linked to reduced quality of life and mortality. Its pathophysiology is complex and there are several forms of treatment proposed in the literature with differing side effect profiles. Many patients do not respond to treatment which warrants augmentation with other treatments and the investigation of novel treatments. One of these treatments includes testosterone therapy which evidence suggests might improve depressed mood in older patients with low levels of testosterone and helps restore physical impairments caused by age-related hormonal changes.

OBJECTIVE

The objective of this review is to synthesize information regarding clinical depression, its treatment options, and the efficacy and safety of testosterone treatment for the treatment of depression.

METHODS

This review utilized comprehensive secondary and tertiary data analysis across many academic databases and published work pertaining to the topic of interest.

RESULTS

Within some subpopulations such as men with dysthymic disorder, treatment resistant depression, or low testosterone levels, testosterone administration yielded positive results in the treatment of depression. Additionally, rodent models have shown that administering testosterone to gonadectomized male animals reduces symptoms of depression. Conversely, some studies have found no difference in depressive symptoms after treatment with testosterone when compared with placebo. It was also noted that over administration of testosterone is associated with multiple adverse effects and complications.

CONCLUSION

The current evidence provides mixed conclusions on the effectiveness of testosterone therapy for treating depression. More research is needed in adult men to see if declining testosterone levels directly influence the development of depression.

Individual characteristics of adolescent psychiatric patients accessing psychotherapy in China

Most mental health problems develop during childhood and adolescence, so identifying the mental health needs and care pathways of adolescents is crucial to improving prevention. This study aimed to understand the characteristics of adolescent patients with mental disorders receiving psychotherapy in China. Data were collected retrospectively from the psychotherapy records of 116 patients at the Weifang Mental Health Centre. Information collected included demographics, stressors, duration of psychotherapy, and clinical diagnosis. Chi-square tests and negative binomial regression models were used to explore the relationship between demographic and clinical variables. The results showed that depression was the most common diagnosis, followed by anxiety and stress-related disorders and bipolar and related disorders. Rural patients were more likely to report family stress, while urban patients were more likely to report school stress. Female patients were more likely to report family stress and to be diagnosed with depression. Family stress, social stress, school stress, patient origin and economic conditions were all significant predictors of the duration of psychological treatment. This study helps to understand the characteristics and psychotherapeutic needs of adolescents with mental disorders who receive psychotherapy in China so that the positive role of psychotherapy in the prevention, treatment and rehabilitation of mental disorders can be better utilised.

Association between relapses, stress, and depression in people with multiple sclerosis during the COVID-19 pandemic

Background

Stress is a potential trigger for clinical and radiological activity in Multiple Sclerosis (MS). COVID-19 pandemic has been a relevant source of mental distress in people with MS (pwMS) and deeply impacted on disease management.

Objective

To investigate the association between stress, anxiety, depression, and risk of relapse during the COVID-19 pandemic.

Methods

From an electronic database used for clinical practice, we extracted data of relapsing–remitting (RR) or relapsing-progressive (RP) MS patients and calculated the annualized relapse rate (ARR) during 2019 and 2020. From 01/12/2020 to 30/12/2020, enrolled patients were invited to fill in a Google Forms survey to investigate depression, anxiety, stress, and Post-Traumatic Stress Disorder (PTSD).

Results

We selected 216 patients with RR or RP-MS to calculate ARR: compared to 2019, in 2020 there was a significant increase in ARR (p = 0.0142).

Over 216 selected pwMS, 154 completed the survey. Matching the survey responses and incidence of relapses in 2020, there was a significant association between relapses and stress (p = 0.030) and relapses and depression (p = 0.011), but not between relapses and anxiety (p = 0.130) or PTSD (p = 0.279).

Conclusions

Our results support the hypothesis that pandemic-related stress is associated to clinical exacerbations, both as a possible consequence of the COVID-19 impact on MS care.

The Cortisol and ACTH Response to Dex/CRH Testing in Women With and Without Perimenopausal Depression

CONTEXT

Abnormalities in the hypothalamic-pituitary-adrenal (HPA) axis are frequent accompaniments of depression, and studies have documented the role of stress and stressful life events in the ontogeny of perimenopausal depressions (PMD). Because HPA axis function in women is further modulated both by aging and ovarian steroids, it is possible that a dysregulated HPA axis contributes to the increased risk of PMD.

OBJECTIVE

We examined HPA axis function in perimenopausal women with and without depression using the combined dexamethasone-corticotropin-releasing hormone (Dex/CRH) test.

METHODS

Dex/CRH tests were performed on 20 women with PMD and 20 women who were also perimenopausal but without current or past depression (control women). Main outcome measures were plasma levels of cortisol and adrenocorticotropin (ACTH) and 24-hour urinary free cortisol (UFC). Five women took chronic stable medications, otherwise all women were medically healthy, and both groups were comparable with respect to reproductive stage and age. Standardized symptom rating scales were administered to each woman prior to Dex/CRH testing.

RESULTS

No group differences were present in either baseline or stimulated ACTH and cortisol secretion. Baseline plasma measures of estradiol, progesterone, and 24-hour UFC levels similarly did not differ in PMD and control women.

CONCLUSION

Despite reports of increased stress responsiveness in PMD, we observed no abnormalities of HPA axis activity associated with PMD compared with women without depression. These findings suggest that PMD is not uniformly associated with HPA dysregulation and could reflect underlying pathophysiologic processes that are distinct from women with nonreproductive-related depressions.

Endogenous cannabinoid levels and suicidality in combat veterans

Combat veterans are at elevated suicide risk. The goal of this study was to test the hypothesis that combat veterans who have made a suicide attempt post-deployment can be distinguished from combat veterans who have never made a suicide attempt based on differences in psychological and biological variables. For the latter, we focused on endogenous cannabinoids, neuroendocrine markers that are associated with stress. Demographic and clinical parameters of suicide attempters and non-attempters were assessed. Blood samples were assayed for anandamide (AEA), 2-arachidonoylglycerol (2-AG), and cortisol. Suicide attempters had higher Scale for Suicidal Ideation (SSI) scores in comparison to non-attempters. Controlling for gender, 2-AG levels were higher among suicide attempters in comparison to non-attempters. Cortisol levels positively correlated with 2-AG levels and negatively correlated with SSI scores among non-attempters but not among attempters. AEA levels negatively correlated with SSI scores among attempters but not among non-attempters. Our results indicate that there are psychological and biological differences between combat veterans with or without a history of suicidal attempt. Our findings also suggest that clinically observed differences between the groups may have a neurobiological basis.

Handgrip Strength is Associated with Psychological Functioning, Mood and Sleep in Women over 65 Years

Background: The predictive nature of handgrip strength (HGS) was analyzed, showing a direct association with the functional domains of health, cognitive and social levels, and some inverse association with depressive values. Aim: To analyze the relationship between HGS and the psychological functioning of older people, such as depression, mood and sleep. Method: A total of 38 women, participated in this study (age = 72.29 ± 5.21 year). As measurement instruments a hand dynamometer was used for HGS, Profile of Mood Status (POMS) 29 was used for mood, the geriatric depression scale was used for depression, and the Oviedo questionnaire was used for sleep. A cluster analysis was performed taking into account the performance in the HGS. Results: The group that obtained a high HGS result showed a better total score for vigor, depression, insomnia and sleep. Pearson correlation analysis showed significant correlations between HGS and vigor, depression, insomnia and sleep total score. Conclusion: HGS in women over 65 years was associated with psychological functioning and sleep quality.

Sex differences in depression: Insights from clinical and preclinical studies

Depression represents a global mental health concern, and disproportionally affects women as they are twice more likely to be diagnosed than men. In this review, we provide a summary of evidence to support the notion that differences in depression between men and women span multiple facets of the disease, including epidemiology, symptomology, treatment, and pathophysiology. Through a lens of biological sex, we overview depression-related transcriptional patterns, changes in neuroanatomy and neuroplasticity, and immune signatures. We acknowledge the unique physiological and behavioral demands of pregnancy and motherhood by devoting special attention to depression occurring in the peripartum period. Specifically, we discuss issues surrounding the presentation, time course, treatment, and neurobiology of peripartum depression. We write this review with the intention of highlighting the encouraging advancements in our understanding of sex differences in depression, while underscoring the gaps that remain. A more systematic consideration of biological sex as a variable in depression research will be critical in the discovery and development of pharmacotherapies that are efficacious for both men and women.

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.

What is mood? A computational perspective

The neurobiological understanding of mood, and by extension mood disorders, remains elusive despite decades of research implicating several neuromodulator systems. This review considers a new approach based on existing theories of functional brain organisation. The free energy principle (a.k.a. active inference), and its instantiation in the Bayesian brain, offers a complete and simple formulation of mood. It has been proposed that emotions reflect the precision of - or certainty about - the predicted sensorimotor/interoceptive consequences of action. By extending this reasoning, in a hierarchical setting, we suggest mood states act as (hyper) priors over uncertainty (i.e. emotions). Here, we consider the same computational pathology in the proprioceptive and interoceptive (behavioural and autonomic) domain in order to furnish an explanation for mood disorders. This formulation reconciles several strands of research at multiple levels of enquiry.

Glucocorticoid receptor gene (NR3C1) DNA methylation in association with trauma, psychopathology, transcript expression, or genotypic variation: A systematic review

The glucocorticoid receptor gene (NR3C1) is a critical component of the stress response system. Cytosine methylation of NR3C1 has been repeatedly associated with trauma and mental disorders, including major depression, post-traumatic stress disorder, anxiety, and personality disorders, suggesting that NR3C1 methylation may play a role in stress-related psychopathology. We systematically reviewed 55 studies examining NR3C1 DNA methylation in association with trauma exposure, psychopathology, gene expression, and/or common genetic variants. Overall, a number of NR3C1 CpG sites were significantly associated with trauma or psychopathology, but significant findings were often inconsistent across studies. This lack of consistency is likely influenced by significant methodological variability - experimentally and analytically - across studies. Selected common genetic variants show no significant effect on NR3C1 CpG methylation. In contrast, there was ample evidence linking increased methylation of NR3C1 to reduced expression of this gene. The inverse association between methylation and gene expression shown across eight out of ten studies supports the notion that methylation in the promoter region of NR3C1 is associated with transcriptional silencing.

Antidepressant and anxiolytic effects of the proprietary Chinese medicine Shexiang Baoxin pill in mice with chronic unpredictable mild stress

Depression and anxiety often co-occur with cardiac diseases. The Shexiang Baoxin pill (SBP) is a proprietary Chinese medicine initially used to treat cardiac conditions. This study explored whether SBP has antidepressant and anxiolytic effects in addition to hormonal and psychotropic mechanisms. Mice underwent 6 weeks of chronic unpredictable mild stress (CUMS) to induce depression- and anxiety-like behavior. During the 6-week experiment, mice received SBP at intragastric doses of 20.25 mg/kg or 40.5 mg/kg daily. Animals were then tested for depression in sucrose preference, forced-swimming, and tail suspension paradigms, and for anxiety in open field and elevated plus maze tests. Both SBP doses significantly reduced anhedonic behavior in the sucrose preference test; the high SBP dose also increased the number of entries into the central zone of the open field. SBP-treated mice had markedly lower blood levels of corticotrophin-releasing hormone (CRH) and adrenocorticotropic hormone (ACTH) than stressed mice treated with vehicle. Either low- or high-dose SBP reversed stress-induced reductions of norepinephrine (NE) and dopamine (DA) metabolites and the expression levels of brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), and glial cell-derived neurotrophic factor (GDNF) in related brain regions. These results suggest that SBP could prevent and alleviate prolonged stress-induced anhedonia and anxiety in association with its suppression of the hypothalamic-pituitary-adrenal (HPA) axis hyperactivity, modulation of brain monoamine neurotransmitter metabolism and neurotrophins. SBP may be particularly suitable for the management of depressive and anxiety disorders in patients with cardiac conditions.

How to measure glucocorticoid receptor's sensitivity in patients with stress-related psychiatric disorders

Stress is a state of derailed homeostasis and a main environmental risk factor for psychiatric diseases. Chronic or uncontrollable stress may lead to a dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, which is a common feature of stress-related psychiatric disorders. One of the key mechanisms underlying a disturbed HPA axis is an impaired function of the glucocorticoid receptor (GR) with an enhanced or reduced feedback sensitivity for glucocorticoids and subsequently altered concentrations of peripheral cortisol. GR function is regulated by a multiprotein complex including the different expression of the hsp90 co-chaperone FK 506 binding protein 51 (FKBP5) that may be genetically determined or acquired in response to stressful stimuli. Specific patterns of a dysregulation of the HPA axis and GR function are found in different stress-related psychiatric entities e.g. major depression, job-related exhaustion or posttraumatic stress disorder. GR challenge tests like the dexamethasone-suppression test (DST), the dexamethasone-corticotropin-releasing hormone (dex-CRH) test or most recently the analysis of the dexamethasone-induced gene expression are employed to sensitively measure HPA axis activity in these disorders. They provide information for a stratification of phenotypic similar but neurobiological diverse psychiatric disorders. In this review we present a synopsis of GR challenge tests with a focus on the application of the DST, the CRH test and the dex-CRH test as well as the dexamethasone-induced gene expression in stress-related psychiatric entities.

Understanding the pathophysiology of depression: From monoamines to the neurogenesis hypothesis model - are we there yet?

A number of factors (biogenic amine deficiency, genetic, environmental, immunologic, endocrine factors and neurogenesis) have been identified as mechanisms which provide unitary explanations for the pathophysiology of depression. Rather than a unitary construct, the combination and linkage of these factors have been implicated in the pathogenesis of depression. That is, environmental stressors and heritable genetic factors acting through immunologic and endocrine responses initiate structural and functional changes in many brain regions, resulting in dysfunctional neurogenesis and neurotransmission which then manifest as a constellation of symptoms which present as depression.

Redefining the endophenotype concept to accommodate transdiagnostic vulnerabilities and etiological complexity

In psychopathology research, endophenotypes are a subset of biomarkers that indicate genetic vulnerability independent of clinical state. To date, an explicit expectation is that endophenotypes be specific to single disorders. We evaluate this expectation considering recent advances in psychiatric genetics, recognition that transdiagnostic vulnerability traits are often more useful than clinical diagnoses in psychiatric genetics, and appreciation for etiological complexity across genetic, neural, hormonal and environmental levels of analysis. We suggest that the disorder-specificity requirement of endophenotypes be relaxed, that neural functions are preferable to behaviors as starting points in searches for endophenotypes, and that future research should focus on interactive effects of multiple endophenotypes on complex psychiatric disorders, some of which are ‘phenocopies’ with distinct etiologies.

Costs and benefits of self-efficacy: Differences of the stress response and clinical implications

Encounters with stressors induce diverse idiosyncratic neuroendocrine, behavioral and psychological reactions across people. Perceived self-efficacy can alter autonomic responses and their effects on mental health. The beneficial effects of self-efficacy in buffering physiological arousal, enhancing performance, and diminishing psychopathological symptoms have been observed in diverse contexts. We show that the role of self-efficacy is not uniformly beneficial, and that higher levels of self-efficacy can sometimes lead to increases in neuroendocrine and psychological stress responses and decreases in performance, a phenomenon that has been widely neglected. We discuss specific conditions under which self-efficacy effects do not uniformly ameliorate or prevent the consequences of stress. These conditions suggest that therapeutic interventions need not always promote self-efficacy in principal. Simultaneously, they to do suggest that keeping self-efficacy high might be disadvantageous or detrimental.

Is Dysregulation of the HPA-Axis a Core Pathophysiology Mediating Co-Morbid Depression in Neurodegenerative Diseases?

There is increasing evidence of prodromal manifestation of neuropsychiatric symptoms in a variety of neurodegenerative diseases such as Parkinson's disease (PD) and Huntington's disease (HD). These affective symptoms may be observed many years before the core diagnostic symptoms of the neurological condition. It is becoming more apparent that depression is a significant modifying factor of the trajectory of disease progression and even treatment outcomes. It is therefore crucial that we understand the potential pathophysiologies related to the primary condition, which could contribute to the development of depression. The hypothalamic-pituitary-adrenal (HPA)-axis is a key neuroendocrine signaling system involved in physiological homeostasis and stress response. Disturbances of this system lead to severe hormonal imbalances, and the majority of such patients also present with behavioral deficits and/or mood disorders. Dysregulation of the HPA-axis is also strongly implicated in the pathology of major depressive disorder. Consistent with this, antidepressant drugs, such as the selective serotonin reuptake inhibitors have been shown to alter HPA-axis activity. In this review, we will summarize the current state of knowledge regarding HPA-axis pathology in Alzheimer's, PD and HD, differentiating between prodromal and later stages of disease progression when evidence is available. Both clinical and preclinical evidence will be examined, but we highlight animal model studies as being particularly useful for uncovering novel mechanisms of pathology related to co-morbid mood disorders. Finally, we purpose utilizing the preclinical evidence to better inform prospective, intervention studies.

Neurobiology of major depressive disorder

We survey studies which relate abnormal neurogenesis to major depressive disorder. Clinically, descriptive gene and protein expression analysis and genetic and functional studies revised here show that individual alterations of a complex signaling network, which includes the hypothalamic-pituitary-adrenal axis; the production of neurotrophins and growth factors; the expression of miRNAs; the production of proinflammatory cytokines; and, even, the abnormal delivery of gastrointestinal signaling peptides, are able to induce major mood alterations. Furthermore, all of these factors modulate neurogenesis in brain regions involved in MDD, and are functionally interconnected in such a fashion that initial alteration in one of them results in abnormalities in the others. We highlight data of potential diagnostic significance and the relevance of this information to develop new therapeutic approaches. Controversial issues, such as whether neurogenesis is the basis of the disease or whether it is a response induced by antidepressant treatments, are also discussed.