Molecular Basis of Late-Life Depression

The biomedical application of inorganic metal nanoparticles in aging and aging-associated diseases

Aging and aging-associated diseases (AAD), including neurodegenerative disease, cancer, cardiovascular diseases, and diabetes, are inevitable process. With the gradual improvement of life style, life expectancy is gradually extended. However, the extended lifespan has not reduced the incidence of disease, and most elderly people are in ill-health state in their later years. Hence, understanding aging and AAD are significant for reducing the burden of the elderly. Inorganic metal nanoparticles (IMNPs) predominantly include gold, silver, iron, zinc, titanium, thallium, platinum, cerium, copper NPs, which has been widely used to prevent and treat aging and AAD due to their superior properties (essential metal ions for human body, easily synthesis and modification, magnetism). Therefore, a systematic review of common morphological alternations of senescent cells, altered genes and signal pathways in aging and AAD, and biomedical applications of IMNPs in aging and AAD is crucial for the further research and development of IMNPs in aging and AAD. This review focus on the existing research on cellular senescence, aging and AAD, as well as the applications of IMNPs in aging and AAD in the past decade. This review aims to provide cutting-edge knowledge involved with aging and AAD, the application of IMNPs in aging and AAD to promote the biomedical application of IMNPs in aging and AAD.

A Transcriptomic Signature of Depressive Symptoms in Late Life

Background

Depressive symptoms in late life can impair daily function and accompany cognitive decline. However, the molecular mechanisms that underlie these changes in the brain remain poorly understood.

Methods

Differential expression analysis was performed on bulk-tissue RNA sequencing data generated from dorsolateral prefrontal cortex samples of elderly participants in ROS/MAP (Religious Orders Study and Memory and Aging Project; N = 998, mean age at death = 89.7 years). Bulk tissue RNA sequencing was analyzed against depressive symptoms measured prior to death, controlling for Alzheimer's disease neuropathology, medication status, and lifestyle factors. Sex-stratified models were also tested.

Results

Increased abundance of the Prader-Willi syndrome-associated gene PWAR1 (corrected p = 5.47 × 10-3) and CTDSPL2 (corrected p = .03) were associated with a higher burden of depressive symptoms in the combined sample. An additional 14 genes showed suggestive associations, including several with known links to neuropsychiatric illness (e.g., ACVR2B-AS1, COL19A1). Functional enrichment analysis revealed downregulation of aerobic metabolism and upregulation of both amino acid catabolism and DNA modification processes. Differential expression signatures were poorly correlated between males and females (Pearson r = 0.12; 95% CI, 0.10 to 0.13), and only the male group showed independently significant differential expression. Little overlap was found with previously published analyses of major depressive disorder.

Conclusions

Building on recently published single-nucleus profiling, we present the largest-ever study of transcriptomic correlates of depressive symptoms in late life, revealing new insights into sex-specific regulators. PWAR1 and CTDSPL2 were identified as putative markers of late-life depression in the dorsolateral prefrontal cortex and warrant further study.

Longitudinal associations between late-life depression, cerebrovascular disease and cognition

BACKGROUND

Depression and vascular disease can both be risk factors for cognitive decline. This study assessed whether indicators of vascular disease are associated with depression over time, and whether depression is associated with cognition independent of vascular disease.

METHODS

Participants were 1032 community-dwelling, older adults from the Sydney Memory and Ageing Study. Depressive symptoms were measured on the 15-item Geriatric Depression Scale, and depression trajectories were classified using latent class growth modelling. Global cognition and individual cognitive domains were assessed. Indicators of vascular disease were history of stroke or transient ischaemic attack (TIA) and total white matter hyperintensities (TWMH). Generalised linear mixed modelling assessed whether vascular markers were associated with change in depressive symptoms over time. Linear mixed modelling examined relationships between depression, vascular disease indicators, and cognition.

RESULTS

History of stroke/TIA or TWMH did not predict depression over time (p = 0.11 and p = 0.70). Baseline stroke/TIA history was associated with a decline in attention over time (b = -0.05, p = 0.04). Significant differences between latent depression trajectories classes in cognitive decline were observed, with participants who became depressed over time experiencing decline in global cognition (b = -0.04, p < 0.001), attention (b = -0.05, p < 0.001) and executive function (b = -0.05, p < 0.001), compared to the non-depressed group.

CONCLUSION

Our findings suggest that depression in later life may not precede cognitive decline. Instead, depressive symptoms and cognitive decline, particularly in attention and executive function, may evolve in tandem over time. This reinforces the importance of early identification and treatment of depression in older adults to potentially mitigate cognitive deterioration.

Ginkgo biloba L. leaf extract (EGb 761) alleviates reserpine-induced depression-like symptoms in aged rats by enhancing serotonin/norepinephrine levels and reducing oxidative/nitrosative stress

Along with accelerated aging, the prevalence of late-life depression (LLD) exacerbates. Older people are more vulnerable to the adverse effects of antidepressants than the young. Therefore, creating antidepressants from medicinal herbs that are more effective and safer is inevitable. Ginkgo biloba L. leaf extract (EGb761) is broadly applied for treating various neuronal dysfunctions. The present study aimed to evaluate the ameliorative and antidepressant effects of EGb761 against reserpine (RES)-induced depression like symptoms and associated comorbidities in aged female rats. Besides, it compared its efficacy with the antidepressant duloxetine (DULX), offering a more comprehensive understanding of therapeutic potential of EGb 761. Rats grouped into control group, EGb 761-H group, RES group, RES plus either EGb 761-L, EGb 761-H, or DULX groups. The antidepressant effects of EGb 761 were evaluated through a series of behavioral tests, measurement of depression biochemical markers, performing neuronal histopathology and immunohistochemical analyses. EGb 761 significantly attenuated behavioral deficits in the open field test and reduced immobility time in the forced swimming test. Moreover, EGb 761 exerted antidepressant-like actions by ameliorating neurotransmitter imbalances, restoring redox homeostasis in cortical region. Also, EGb 761 increased level of ATP, diminished DNA fragmentation, decreased caspase-3 immunoreactivity and increased immunoreactivity of synaptophysin in the cerebral cortex, besides it enhanced the histological architecture of this region. Overall, EGb 761 has the potential effects to manage LLD focus on the role of both serotonergic and noradrenergic systems in mediating these effects, alongside the impact on oxidative/nitrosative stress.

Allium Macrostemon Bge. Attenuates the Cognitive Decline of Aging Mice by Enhancing BDNF/TrkB Pathway

Allium macrostemon Bge. (AM) is a widely utilized culinary spice recognized for its numerous health-promoting properties. Aging-related cognitive impairment (ARCI) represents a significant global health concern during the aging process. However, the potential of AM to attenuate ARCI has not been investigated. This work aims to reveal the effects and potential mechanisms of the water extraction of AM (WEAM) in alleviating ARCI, with a particular emphasis on the BDNF/TrkB signaling pathway. The findings showed a significant enhancement in memory function and a reduction in hippocampal neuronal damage in aging mice following treatment with WEAM, manifested by an increased spontaneous alternation rate in the Y-maze, prolonged step-through latency, and decreased number of errors in the PAT test, a shortened escape latency and increased platform swimming time and platform crossing times in the MWM test. Additionally, WEAM reduced oxidative stress, elevated the expression of proteins related to synaptic plasticity (SYN and PSD95), and activated the BDNF/TrkB signaling pathway in D-galactose-induced aging mice. To elucidate the mechanism by which WEAM alleviates ARCI, both a TrkB activator (7,8-DHF) and an inhibitor (ANA-12) were employed. The results demonstrated that the effects of WEAM on synaptic plasticity were potentiated by 7,8-DHF and diminished by ANA-12. Finally, 11 chemical compositions of WEAM were analyzed and quantified using HPLC-MS/MS, including macrostemonoside, sarsasapogenin, diosgenin, timosaponin AIII, N-p-trans-coumaroyltyramine, guanosine, adenosine, phenylalanine, adenine, arginine, and valine. These results suggest that AM may serve as a promising culinary spice for mitigating ARCI by promoting the BDNF/TrkB signaling pathway, thereby enhancing synaptic plasticity.

A comparative meta-analysis of structural magnetic resonance imaging studies and gene expression profiles revealing the similarities and differences between late life depression and mild cognitive impairment

BACKGROUND

Late-life depression (LLD) predisposes individuals to cognitive decline, often leading to misdiagnoses as mild cognitive impairment (MCI). Voxel-based morphometry (VBM) can distinguish the profiles of these disorders according to gray matter (GM) volumes. We integrated findings from previous VBM studies for comparative analysis and extended the research into molecular profiles to facilitate inspection and intervention.

METHODS

We comprehensively searched PubMed and Web of Science for VBM studies that compared LLD and MCI cases with matched healthy controls (HCs) from inception to 31st December 2023. We included 13 studies on LLD (414 LLDs, 350 HCs) and 50 on MCI (1878 MCIs, 2046 HCs). Seed-based d Mapping with Permutation of Subject Images (SDM-PSI) was used for voxel-based meta-analysis to assess GM atrophy, spatially correlated with neuropsychological profiles. We then used multimodal and linear-model analysis to assess the similarities and differences in GM volumetric changing patterns. Partial least squares (PLS) regression and gene enrichment were employed for transcription-neuroimaging associations.

RESULTS

GM volumes in the left hippocampus and right parahippocampal gyrus are more affected in MCI, along with memory impairment. MCI was spatially correlated with a more extensive reduction in the levels of neurotransmitters and a severe downregulation of genes related to cellular potassium ion transport and metal ion transmembrane transporter activity.

CONCLUSION

Compared to LLD, MCI exhibited more GM atrophy in the hippocampus and parahippocampal gyrus and lower gene expression of ion transmembrane transport. Our findings provided imaging-transcriptomic-genetic integrative profiles for differential diagnosis and precise intervention between LLD and MCI.

Relationship between hearing loss and depression: A cross-sectional analysis from the National Health and Nutrition Examination Survey 2015-2018

BACKGROUND

Hearing loss is a prevalent issue resulting from loud noise exposure, aging, diseases, and genetic differences. As individuals age, the likelihood of experiencing hearing loss and depression escalates; yet, the link between hearing loss and the risk of depression remains ambiguous. This study explores the relationship between hearing and depression risk, taking into account sociodemographic and health-related factors.

METHODS

Using data from the National Health and Nutrition Examination Survey (NHANES) 2015-2018, a cross-sectional analysis was conducted, focusing on adult participants. It evaluated their hearing status and depression levels using the Patient Health Questionnaire-9 (PHQ-9). The study examined a range of variables, such as age, gender, socioeconomic status, lifestyle choices, and comorbidities, to understand their influence on the link between hearing loss and depression.

RESULTS

Analysis indicated a significant association between moderate to severe hearing loss and an increased risk of depression, notably in older adults. This relationship remained significant even after adjusting for a variety of sociodemographic and health factors.

LIMITATIONS

This is a study using the NHANES database using self-reported surveys.

CONCLUSION

The findings of this study emphasize the need to integrate hearing health in the holistic assessment and treatment of depression, particularly advocating for combined care strategies for the elderly.

Choice intention for the national volume-based procurement drug and its associated factors: a cross-sectional study on patients with late-life depression in China

BACKGROUND

The national volume-based procurement (NVBP) policy has significantly decreased prices and increased the accessibility of NVBP drugs. Nevertheless, issues such as heightened adverse reactions and suboptimal efficacy have arisen. Concerns regarding the quality of low-cost medications and the absence of long-term research have been widely recognized. This has led to caution among patients with late-life depression (LLD) due to their delicate health and the severity of their condition. This study evaluated the choice intention for NVBP drugs and associated factors in older patients with LLD.

METHODS

A weighted sample of 408 participants between December 2022 and March 2023 were included. Data were collected via face-to-face interviews and questionnaires. To identify significant associated factors of choice intention, a multilevel logistic regression model was employed.

RESULTS

Over half (53.68%) of older patients with LLD intended to choose NVBP drugs. Associated factors included self-assessed poor economy, higher out-of-pocket expenses, monthly household income exceeding CNY 6000, absence of other non-communicable chronic diseases, ordinary registration, urban employee medical insurance, no requirements for brand-name drugs, adverse reactions after using NVBP drugs, and rejection of physicians' recommendation for NVBP drugs. The interaction effect between the real economic condition and patients self-assessed economy significantly influences choice intention for NVBP drugs. Among 124 patients with self-assessed poor economy, 75 showed a higher intention to use NVBP drugs. In these patients, age, medical insurance reimbursement, and brand awareness were significantly associated with choice intention.

CONCLUSION

Economic factors, physical conditions, medical needs, and physician recommendations significantly influenced the choice intention for NVBP drugs. The choice intention can be improved by strengthening physician-patient communication, increasing the scope and proportion of medical insurance reimbursement, improving substitution studies, and conducting post-marketing re-evaluations of NVBP drugs.

Is there evidence for using ketamine among individuals with dementia?

The aim of this short narrative review was to evaluate the existing literature regarding the clinical use of ketamine among individuals with dementia, especially those with behavioral disturbances. PubMed, Cochrane, and Ovid (Embase, APA PsycINFO, and MEDLINE) databases were searched for abstracts using the search terms "ketamine" AND "dementia." Only articles describing the use of ketamine in individuals with dementia were included. Articles that did not include individuals with dementia, did not use ketamine, were published in a non-English language, primarily described animal studies, or were reviews were excluded. Three case reports met the inclusion criteria. One described the use of subcutaneous ketamine for depression, one described the use of intramuscular ketamine for acute agitation, and one described the use of S-ketamine as anesthesia during electroconvulsive therapy for depression and catatonia. No significant adverse effects were reported in any of the cases. Although the use of ketamine in the treatment of depression and agitation associated with dementia has potential, the current evidence remains limited. High-quality prospective studies are needed to confirm the observations of these case reports before ketamine can be used to treat behavioral disturbances in individuals with dementia.

Impacts of inflammatory cytokines on depression: a cohort study

BACKGROUND

Inflammatory factors are associated with depression. We seek to investigate the correlation between inflammatory cytokines and prognosis of depression or suicidal ideation and behavior at 3 months in depression patients.

METHODS

Eighty-two depressed outpatients were recruited and treated as usual. Plasma cytokines were measured at baseline. Patients were followed up with Patient Health Questionnaire-9 and suicidal ideation and behavior according to the item 3 of Hamilton depression scale for 3 months.

RESULTS

Compared to the depression patients with low level of interleukin-1β, the high one had severe depressive symptoms at month 2 and 3 (B 0.92, P < 0.01; B 0.86, P = 0.02; respectively). The incidence of suicidal ideation or behavior was 18.3% at 3 months. Depression patients with high levels of tumor necrosis factor-α showed high risk of suicidal ideation and behavior than the low one (OR 2.16, 95% CI 1.00-4.65, P = 0.04).

CONCLUSIONS

High levels of interleukin-1β and tumor necrosis factor-α were predictive of middle-term severe depressive symptoms and suicidal ideation and behavior respectively.

Gut Microbiota Dysbiosis and Inflammation Dysfunction in Late-Life Depression: An Observational Cross-Sectional Analysis

Purpose

There are some challenges to diagnosis in the context of similar diagnostic criteria for late-life depression (LLD) and adult depression due to cognitive impairment and other clinical manifestations. The association between gut microbiota and inflammation remains unclear in LLD. We analyzed gut microbiota characteristics and serum inflammatory cytokines in individuals with LLD to explore the combined role of these two factors in potential biomarkers of LLD.

Methods

This was an observational cross-sectional study. Fecal samples and peripheral blood from 29 patients and 33 sex- and age-matched healthy controls (HCs) were collected to detect gut microbiota and 12 inflammatory factors. We analyzed differences in diversity and composition of gut microbiota and evaluated relations among gut microbiota, inflammatory factors, and neuropsychological scales. We extracted potential biomarkers using receiver-operating characteristic curve analysis to predict LLD utilizing the combination of the microbiota and inflammatory cytokines.

Results

Elevated systemic inflammatory cytokine levels and gut microbiota dysbiosis were found in LLD patients. Relative abundance of Verrucomicrobia at the phylum level and Megamonas, Citrobacter, and Akkermansia at the genus level among LLD patients was lower than HCs. Abundance of Coprococcus, Lachnobacterium, Oscillospira, and Sutterella was higher in LLD patients. Notably, IL6, IFNγ, Verrucomicrobia, and Akkermansia levels were correlated with depression severity. Our study identified IL6, Akkermansia, and Sutterella as predictors of LLD, and their combination achieved an area under the curve of 0.962 in distinguishing LLD patients from HCs.

Conclusion

This research offers evidence of changes within gut microbiota and systemic inflammation in LLD. These findings possibly help elucidate functions of gut microbiota and systemic inflammation in LLD development and offer fresh ideas on biomarkers for clinical practise in the context of LLD.

The protective role of ginsenoside Rg3 in heart diseases and mental disorders

Ginsenoside Rg3, a compound derived from Panax ginseng C. A. Mey., is increasingly recognized for its wide range of pharmacological effects. Under the worldwide healthcare challenges posed by heart diseases, Rg3 stands out as a key subject in modern research on Chinese herbal medicine, offering a novel approach to therapy. Mental illnesses are significant contributors to global disease mortality, and there is a well-established correlation between cardiac and psychiatric conditions. This connection is primarily due to dysfunctions in the sympathetic-adrenomedullary system (SAM), the hypothalamic-pituitary-adrenal axis, inflammation, oxidative stress, and brain-derived neurotrophic factor impairment. This review provides an in-depth analysis of Rg3's therapeutic benefits and its pharmacological actions in treating cardiac and mental health disorders respectively. Highlighting its potential for the management of these conditions, Rg3 emerges as a promising, multifunctional therapeutic agent.

Distinguishing features of depression in dementia from primary psychiatric disease

Depression is a common and devastating neuropsychiatric symptom in the elderly and in patients with dementia. In particular, nearly 80% of patients with Alzheimer's Disease dementia experience depression during disease development and progression. However, it is unknown whether the depression in patients with dementia shares the same molecular mechanisms as depression presenting as primary psychiatric disease or occurs and persists through alternative mechanisms. In this review, we discuss how the clinical presentation and treatment differ between depression in dementia and as a primary psychiatric disease, with a focus on major depressive disorder. Then, we hypothesize several molecular mechanisms that may be unique to depression in dementia such as neuropathological changes, inflammation, and vascular events. Finally, we discuss existing issues and future directions for investigation and treatment of depression in dementia.

[Comorbidity of depression and dementia: epidemiological, biological and therapeutic aspects]

The literature review is devoted to the problem of the relationship between dementia and depression, the role of depression as a risk factor for dementia and the place of depression in the structure of neurocognitive disorders in dementia. Epidemiological data are presented and the mechanisms of interrelation of disorders are considered. The search for sources included only qualitative research, meta-analyses, full-text articles and was conducted in the PubMed, Google system using the keywords «dementia, depression». The presented epidemiological and biological data indicate that depression increases the risk of dementia, confirming the hypothesis of a causal factor. The main directions of research on the relationship between depression and dementia in the context of Alzheimer's disease prevention are given.

Serum levels of biomarkers that may link chronic obstructive pulmonary disease and depressive disorder

BACKGROUND

Depressive disorder is a common comorbidity of chronic obstructive pulmonary disease (COPD); according to some studies, it occurs in approximately 80% of patients. The presence of depressive symptoms influences the quality of life and affects the course and treatment of this disease. The cause of depressive symptoms in COPD and the linking mechanism between COPD and depressive disorder have not been clearly elucidated, and more studies are warranted. Inflammation and inflammation-related processes and biomarkers are involved in the etiology of COPD and depressive disorder and may be an explanation for the potential occurrence of depressive disorder in patients diagnosed with COPD. The scope of this study was to measure and compare the profiles of IL-18, TGF-β, RANTES, ICAM-1, and uPAR among stable COPD patients, recurrent depressive disorder (rDD) patients, and healthy controls.

METHODS

Inflammation and inflammation-related factors were evaluated in COPD patients, patients diagnosed with depressive disorder, and control individuals using enzyme-linked immunosorbent assays.

RESULTS

Interleukin (IL)-18, transforming growth factor (TGF)-β, chemokine RANTES, and urokinase plasminogen activator receptor (uPAR) concentrations were higher in patients suffering from COPD and depression than in control patients. Intercellular adhesive molecule (ICAM)-1 levels were significantly higher in COPD patients and lower in depressive disorder patients than in controls.

CONCLUSIONS

Higher levels of IL-18, TGF-β, RANTES, and uPAR in patients with COPD might indicate the presence of depressive disorder and suggest the need for further evaluation of the mental state of these patients.

Arketamine for cognitive impairment in psychiatric disorders

Cognitive impairment has been observed in patients with various psychiatric disorders, including schizophrenia, major depressive disorder (MDD), and bipolar disorder (BD). Although modern therapeutic drugs can improve certain symptoms (i.e., psychosis, depression) in these patients, these drugs have not been found to improve cognitive impairment. The N-methyl-D-aspartate receptor antagonist (R,S)-ketamine has attracted attention as a rapidly acting antidepressant. In addition to its robust antidepressant effects, (R,S)-ketamine has been suggested to improve cognitive impairment in patients with MDD and BD, despite causing cognitive impairment in healthy control subjects. (R,S)-ketamine is a racemic mixture of equal amounts of (R)-ketamine (or arketamine) and (S)-ketamine (or esketamine). Arketamine has been found to have more potent antidepressant-like actions than esketamine in rodents. Interestingly, arketamine, but not esketamine, has been suggested to improve phencyclidine-induced cognitive deficits in mice. Furthermore, arketamine has been suggested to ameliorate cognitive deficits in rodent offspring after maternal immune activation. In the current article, it is proposed that arketamine has therapeutic potential for treating cognitive impairment in patients with psychiatric disorders. Additionally, the potential role of the gut-microbiome-brain axis in cognitive impairment in psychiatric disorders is discussed.

Neural complexity EEG biomarkers of rapid and post-rapid ketamine effects in late-life treatment-resistant depression: a randomized control trial

Ketamine is an effective intervention for treatment-resistant depression (TRD), including late-in-life (LL-TRD). The proposed mechanism of antidepressant effects of ketamine is a glutamatergic surge, which can be measured by electroencephalogram (EEG) gamma oscillations. Yet, non-linear EEG biomarkers of ketamine effects such as neural complexity are needed to capture broader systemic effects, represent the level of organization of synaptic communication, and elucidate mechanisms of action for treatment responders. In a secondary analysis of a randomized control trial, we investigated two EEG neural complexity markers (Lempel-Ziv complexity [LZC] and multiscale entropy [MSE]) of rapid (baseline to 240 min) and post-rapid ketamine (24 h and 7 days) effects after one 40-min infusion of IV ketamine or midazolam (active control) in 33 military veterans with LL-TRD. We also studied the relationship between complexity and Montgomery-Åsberg Depression Rating Scale score change at 7 days post-infusion. We found that LZC and MSE both increased 30 min post-infusion, with effects not localized to a single timescale for MSE. Post-rapid effects of reduced complexity with ketamine were observed for MSE. No relationship was observed between complexity and reduction in depressive symptoms. Our findings support the hypothesis that a single sub-anesthetic ketamine infusion has time-varying effects on system-wide contributions to the evoked glutamatergic surge in LL-TRD. Further, changes to complexity were observable outside the time-window previously shown for effects on gamma oscillations. These preliminary results have clinical implications in providing a functional marker of ketamine that is non-linear, amplitude-independent, and represents larger dynamic properties, providing strong advantages over linear measures in highlighting ketamine's effects.

Chronic unpredictable stress induces depression/anxiety-related behaviors and alterations of hippocampal monoamine receptor mRNA expression in female mice at different ages

Depression and anxiety are the most common mental health disorders. Though they affect people at any age and occur more often in females, the pathophysiological changes under these conditions are less investigated. In the present study, we examined the effects of age and stress on depression- and anxiety-related behaviors in female mice. Saccharin preference and the open field test were carried out before and after chronic unpredictable stress in 4-, 14- and 25-month-old female mice. After behavioral tests, mRNA levels of monoamine receptors in the hippocampus were measured by real-time RT-PCR. Chronic unpredictable stress decreased saccharin preference in 4-, 14- and 25-month-old mice and the time spent in the center in the open field test in 25-month-old mice. For monoamine receptors, analysis of variance revealed significant effects of age on mRNA levels of Htr1a, Htr2a, Htr6, Adra1a, Adrb2, and Adrb3, significant effects of stress on mRNA levels of Htr4, Adra2c, Adrb1, and Adrb2, and interactions of age × stress on mRNA levels of Htr1a, Htr5b, Adra1d, Adra2a, Adra2c, and Adrb1. Chronic unpredictable stress decreased mRNA levels of Htr4, Htr5b, Adra2c, and Adrb1 in 4-month-old female mice. Correlations were observed between saccharin preference and mRNA levels of Htr4, Htr5b, Htr6, Adra1d, Adra2a, and Adra2c in 4-month-old mice and between the time spent in the center in the open field test and mRNA levels of Htr1b in 4-month-old mice, Htr3a, Htr7, and Adrb2 in 14-month-old mice, and Drd2 in 4- and 14-month-old mice. Our findings support that stress induces depression- and anxiety-related behaviors and the expression of hippocampal monoamine receptors in an age-dependent manner in female mice.

The heterogeneity of late-life depression and its pathobiology: a brain network dysfunction disorder

Depression is frequent in older individuals and is often associated with cognitive impairment and increasing risk of subsequent dementia. Late-life depression (LLD) has a negative impact on quality of life, yet the underlying pathobiology is still poorly understood. It is characterized by considerable heterogeneity in clinical manifestation, genetics, brain morphology, and function. Although its diagnosis is based on standard criteria, due to overlap with other age-related pathologies, the relationship between depression and dementia and the relevant structural and functional cerebral lesions are still controversial. LLD has been related to a variety of pathogenic mechanisms associated with the underlying age-related neurodegenerative and cerebrovascular processes. In addition to biochemical abnormalities, involving serotonergic and GABAergic systems, widespread disturbances of cortico-limbic, cortico-subcortical, and other essential brain networks, with disruption in the topological organization of mood- and cognition-related or other global connections are involved. Most recent lesion mapping has identified an altered network architecture with "depressive circuits" and "resilience tracts", thus confirming that depression is a brain network dysfunction disorder. Further pathogenic mechanisms including neuroinflammation, neuroimmune dysregulation, oxidative stress, neurotrophic and other pathogenic factors, such as β-amyloid (and tau) deposition are in discussion. Antidepressant therapies induce various changes in brain structure and function. Better insights into the complex pathobiology of LLD and new biomarkers will allow earlier and better diagnosis of this frequent and disabling psychopathological disorder, and further elucidation of its complex pathobiological basis is warranted in order to provide better prevention and treatment of depression in older individuals.

Activation of CREB-BDNF Pathway in Pyramidal Neurons in the Hippocampus Improves the Neurological Outcome of Mice with Ischemic Stroke

Cerebral ischemia is characterized by several pathological reaction evolving over time. Hyperactivation of glutamatergic neurons is the main factor leading to excitotoxicity which potentiates oxidative stress and triggers the mechanisms of neural apoptosis after cerebral ischemia. However, it is unclear whether glutamate in the ventral hippocampal Cornus Ammonis 1 (vCA1) acts a part in neurological deficits, pain perception, anxiety, and depression induced by ischemic stroke. We investigated the effects of chemogenetic inhibition or activation of vCA1 pyramidal neurons which are mainly glutamatergic neurons on sequelae induced by cerebral ischemia. Our results revealed that inhibition of vCA1 pyramidal neurons by chemogenetics alleviated neurological deficits, pain perception, anxiety, and depression caused by cerebral ischemia in mice, but activation of vCA1 pyramidal neurons had limited effects. Moreover, we found that stroke was accompanied by decreased levels of cAMP-response element-binding protein (CREB) and brain-derived neurotrophic factor (BDNF) in vCA1, which are modulated by glutamate. In this study, overexpression of CREB protein in pyramidal neurons in vCA1 by AAV virus significantly upregulated the content of BDNF and ameliorated the dysfunction induced by ischemic stroke. Our results demonstrated activation of the CREB-BDNF pathway in vCA1 pyramidal neurons significantly improved neurological deficits, pain perception, anxiety, and depression induced by ischemic stroke.

Neuroinflammation and Oxidative Stress in the Pathogenesis of Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a neurodevelopmental disorder (NDD) characterized by impairments in social communication, repetitive behaviors, restricted interests, and hyperesthesia/hypesthesia caused by genetic and/or environmental factors. In recent years, inflammation and oxidative stress have been implicated in the pathogenesis of ASD. In this review, we discuss the inflammation and oxidative stress in the pathophysiology of ASD, particularly focusing on maternal immune activation (MIA). MIA is a one of the common environmental risk factors for the onset of ASD during pregnancy. It induces an immune reaction in the pregnant mother’s body, resulting in further inflammation and oxidative stress in the placenta and fetal brain. These negative factors cause neurodevelopmental impairments in the developing fetal brain and subsequently cause behavioral symptoms in the offspring. In addition, we also discuss the effects of anti-inflammatory drugs and antioxidants in basic studies on animals and clinical studies of ASD. Our review provides the latest findings and new insights into the involvements of inflammation and oxidative stress in the pathogenesis of ASD.

Major depression, physical health and molecular senescence markers abnormalities

Previous studies suggested the role of cellular senescence in late-life depression (LLD). However, it is unclear how this finding relates to common features of LLD, such as medical and cognitive problems. We applied factor analyses to an extensive battery of clinical variables in 426 individuals with LLD. Here we tested the relationship between these factors, age and sex, with an index of cellular senescence based on 22 senescence-associated secretory phenotype proteins. We found four factors: 'depression and anxiety severity', 'cognitive functioning', 'cardiovascular and cardiometabolic health' and 'blood pressure'. A higher senescence-associated secretory phenotype index was associated with poorer 'cognitive functioning' and 'cardiovascular and cardiometabolic health' but not with 'depression and anxiety severity'. These findings highlight the role of cellular senescence in poorer physical and cognitive health in LLD. They are consonant with the viewpoint that co-occurring medical burdens and their associated disabilities are part of a phenotype of accelerated ageing in LLD.

Age-Related Alterations in the Level and Metabolism of Serotonin in the Brain of Males and Females of Annual Turquoise Killifish (Nothobranchius furzeri)

The annual turquoise killifish (Nothobranchius furzeri) is a laboratory model organism for neuroscience of aging. In the present study, we investigated for the first time the levels of serotonin and its main metabolite, 5-hydroxyindoleacetic acid, as well as the activities of the key enzymes of its synthesis, tryptophan hydroxylases, and degradation, monoamine oxidase, in the brains of 2-, 4- and 7-month-old male and female N. furzeri. The marked effect of age on the body mass and the level of serotonin, as well as the activities of tryptophan hydroxylases and monoamine oxidase in the brain of killifish were revealed. The level of serotonin decreased in the brain of 7-month-old males and females compared with 2-month-old ones. A significant decrease in the tryptophan hydroxylase activity and an increase in the monoamine oxidase activity in the brain of 7-month-old females compared to 2-month-old females was shown. These findings agree with the age-related alterations in expression of the genes encoding tryptophan hydroxylases and monoamine oxidase. N. furzeri is a suitable model with which to study the fundamental problems of age-related changes of the serotonin system in the brain.

Late-life depression: Epidemiology, phenotype, pathogenesis and treatment before and during the COVID-19 pandemic

Late-life depression (LLD) is one of the most common mental disorders among the older adults. Population aging, social stress, and the COVID-19 pandemic have significantly affected the emotional health of older adults, resulting in a worldwide prevalence of LLD. The clinical phenotypes between LLD and adult depression differ in terms of symptoms, comorbid physical diseases, and coexisting cognitive impairments. Many pathological factors such as the imbalance of neurotransmitters, a decrease in neurotrophic factors, an increase in β-amyloid production, dysregulation of the hypothalamic-pituitary-adrenal axis, and changes in the gut microbiota, are allegedly associated with the onset of LLD. However, the exact pathogenic mechanism underlying LLD remains unclear. Traditional selective serotonin reuptake inhibitor therapy results in poor responsiveness and side effects during LLD treatment. Neuromodulation therapies and complementary and integrative therapies have been proven safe and effective for the treatment of LLD. Importantly, during the COVID-19 pandemic, modern digital health intervention technologies, including socially assistive robots and app-based interventions, have proven to be advantageous in providing personal services to patients with LLD.

[Prognosis of late-life depression: clinical and immunological features]

OBJECTIVE

To study the outcomes of depression at a late age during a 3-year prospective follow-up in patients with various immunophenotypes.

MATERIAL AND METHODS

A cohort of patients with depressive disorders who were treated in a gerontopsychiatric hospital and re-examined after 1 and 3 years. The group with immunophenotype A (with increased activity of leukocyte elastase (LE) and complex depressions, comorbid with anxiety and senesto-hypochondriac disorders) included 20 people: 6 men (30%) and 14 women (70%), median age was 68 years. A depressive episode (DE) was diagnosed in 13 patients (65%) with recurrent depressive disorder (RDD) and in 7 patients (35%) with bipolar affective disorder (BAD). The group with immunophenotype B (with reduced activity of LE and prolonged apathetic-adynamic depression) included 31 people: 10 men (32.3%) and 21 women (67.7%), the median age was 68 years. DE was diagnosed in 20 patients (64.5%) with RDD, 9 patients (29%) with BAD, and in 2 patients (6.5%) with a single DE. The patients were examined using clinical, psychometric, immunological and clinical- follow-up methods (after 1 and 3 years).

RESULTS

More favorable course of the disease with the formation of high-quality remission was observed in patients with immunophenotype A (95% of cases after 1 and 3 years; χ2=10.44; p=0.001 and χ2=11.97; p=0.001, respectively). In patients with immunophenotype B, an unfavorable course of the disease prevailed (83.9 and 87.1% of cases after 1 and 3 years) with the formation of low-quality remissions (with residual depressive disorders, the development of repeated depressive phases and chronification of depression).

CONCLUSION

The study revealed the relationship between clinical and biological features and the course of late-life depression.

Late-Onset Depression but not Early-Onset Depression may Increase the Risk of All-Cause Mortality in Older Age: 8-Year Follow-Up of the Salus in Apulia Study

OBJECTIVES

Individuals with late-life depression (LLD) may have shorter survival, but there is a lack of findings in population-based settings about health-related outcomes of LLD and its subtypes: early-onset depression (EOD) and late-onset depression (LOD). We aimed to evaluate the risk of all-cause mortality of individuals with LLD and its subtypes in an older population-based cohort. Moreover, we investigated whether inflammatory, cognitive, genetic features and multimorbidity could modify the effect of this association.

DESIGN

Longitudinal population-based study with 8-year follow-up.

SETTING AND PARTICIPANTS

We analyzed data on a sample of 1479 participants, all aged >65 years, in the Salus in Apulia Study.

METHODS

LLD was diagnosed through DSM-IV-TR criteria and LOD and EOD according to the age of onset. Multimorbidity status was defined as the copresence of 2 or more chronic diseases.

RESULTS

The overall prevalence of LLD in this older sample from Southern Italy was 10.2%, subdivided into 3.4% EOD and 6.8% LOD. In multivariable Cox models adjusted for age, gender, education, global cognition, apolipoprotein E ε4 allele, physical frailty, interleukin-6, and multimorbidity, LLD showed a greater risk of all-cause mortality. LOD differed from EOD regarding gender, education, cognitive dysfunctions, and diabetes mellitus. There was a significantly increased risk of all-cause mortality for participants with LOD (hazard ratio:1.99; 95% CI 1.33-2.97) in the time of observation between enrollment date and death date (7.31 ± 2.17 months).

CONCLUSIONS AND IMPLICATION

In older age, individuals with LOD but not with EOD had a significantly decreased survival, probably related to increased inflammation, multimorbidity, and cognitive impairments.

Antidepressant Effect of Ketamine on Inflammation-Mediated Cytokine Dysregulation in Adults with Treatment-Resistant Depression: Rapid Systematic Review

Background

Major depressive disorder (MDD) and treatment-resistant depression (TRD) represent a global source of societal and health burden. To advise proper management of inflammation-related depression among TRD patients, it is important to identify therapeutic clinical treatments. A key factor is related to proinflammatory cytokines such as interleukin- (IL-) 1β, IL-6, and tumor necrosis factor- (TNF-) α which have been implicated in the pathogenesis of depressive symptoms in MDD patients. Ketamine may provide an anti-inflammatory therapeutic strategy by targeting proinflammatory pathways associated with depressive disorders, which may be exacerbated in the ageing population with TRD.

Objective

Despite a burgeoning body of literature demonstrating that inflammation is linked to TRD, there is still a lack of comprehensive research on the relationship between proinflammatory biomarkers and ketamine's antidepressant effect on TRD patients.

Method

The Cochrane Library and PubMed/MEDLINE databases were systematically searched from inception up to February 1, 2022, adopting broad inclusion criteria to assess clinical topics related to the impact of ketamine on inflammatory cytokines in TRD patients. The present work is in compliance with the World Health Organization Rapid Review Guide.

Results

Five out of the seven studies examined in this review show that ketamine infusion may reduce depressive symptoms with a quick start of effect on TRD patients. Based on the Montgomery-Åsberg Depression Rating Scale (MADRS) and Hamilton Depression Rating Scale (HAM-D) scores, the overall response rate for ketamine was 56%; that is, 56% of those treated with ketamine had MADRS/HAM-D scores decreased by at least 50%.

Conclusions

While the anti-inflammatory effects of ketamine modulate specific proinflammatory cytokines, its rapid antidepressant effect on TRD patients remains inconsistent. However, our study findings can provide a reliable basis for future research on how to improve systemic inflammatory immune disorders and mental health. We suggest that ketamine infusion may be part of a comprehensive treatment approach in TRD patients with elevated levels of depression-specific inflammatory biomarkers.

Involvement of inflammatory responses in the brain to the onset of major depressive disorder due to stress exposure

Major depressive disorder (MDD) is a multifactorial disease affected by several environmental factors. Although several potential onset hypotheses have been identified, the molecular mechanisms underlying the pathogenesis of this disorder remain unclear. Several recent studies have suggested that among many environmental factors, inflammation and immune abnormalities in the brain or the peripheral tissues are associated with the onset of MDDs. Furthermore, several stress-related hypotheses have been proposed to explain the onset of MDDs. Thus, inflammation or immune abnormalities can be considered stress responses that occur within the brain or other tissues and are regarded as one of the mechanisms underlying the stress hypothesis of MDDs. Therefore, we introduce several current advances in inflammation studies in the brain that might be related to the pathophysiology of MDD due to stress exposure in this review.

(R)-ketamine as prophylactic and therapeutic drug for neurological disorders: beyond depression

Neurological disorders are the leading cause of disability and the second leading cause of death worldwide. The increasing social and economic burdens of neurological disorders are driven by global population growth and aging. Depression is a common psychiatric symptom in numerous neurological disorders. It is also a risk factor for Alzheimer's disease (AD) and other dementias, Parkinson's disease (PD), and stroke. The rapid-acting and sustained antidepressant actions of (R,S)-ketamine for severe depression was accidentally discovered. Interestingly, (R)-ketamine has greater potency and longer-lasting antidepressant-like effects than (S)-ketamine in rodents. Importantly, its side effects in rodents and humans are lower than those of (R,S)-ketamine and (S)-ketamine. Furthermore, (R)-ketamine could elicit beneficial actions in various rodent models of neurological disorders, including PD, multiple sclerosis (MS), and stroke. In this article, we review the potential of (R)-ketamine as a prophylactic or therapeutic drug for neurological disorders including AD and other dementias, PD, MS, and stroke.

The enigma of vascular depression in old age: a critical update

Depression is common in older individuals and is associated with high disability and increased mortality, yet the factors predicting late-life depression (LLD) are poorly understood. The relationship between of depressive disorder, age- and disease-related processes have generated pathogenic hypotheses and provided new treatment options. LLD syndrome is often related to a variety of vascular mechanisms, in particular hypertension, cerebral small vessel disease, white matter lesions, subcortical vascular impairment, and other processes (e.g., inflammation, neuroimmune regulatory dysmechanisms, neurodegenerative changes, amyloid accumulation) that may represent etiological factors by affecting frontolimbic and other neuronal networks predisposing to depression. The "vascular depression" hypothesis suggests that cerebrovascular disease (CVD) and vascular risk factors may predispose, induce or perpetuate geriatric depressive disorders. It is based on the presence of various cerebrovascular risk factors in many patients with LLD, its co-morbidity with cerebrovascular lesions, and the frequent development of depression after stroke. Other findings related to vascular depression are atrophy of the medial temporal cortex or generalized cortical atrophy that are usually associated with cognitive impairment. Other pathogenetic hypotheses of LLD, such as metabolic or inflammatory ones, are briefly discussed. Treatment planning should consider there may be a modest response to antidepressants, but several evidence-based and novel treatment options for LLD exist, such as electroconvulsive therapy, transcranial magnetic stimulation, neurobiology-based psychotherapy, as well as antihypertension and antiinflammatory drugs. However, their effectiveness needs further investigation, and new methodologies for prevention and treatment of depression in older individuals should be developed.

Pathomechanisms of Vascular Depression in Older Adults

Depression in older individuals is a common complex mood disorder with high comorbidity of both psychiatric and physical diseases, associated with high disability, cognitive decline, and increased mortality The factors predicting the risk of late-life depression (LLD) are incompletely understood. The reciprocal relationship of depressive disorder and age- and disease-related processes has generated pathogenic hypotheses and provided various treatment options. The heterogeneity of depression complicates research into the underlying pathogenic cascade, and factors involved in LLD considerably differ from those involved in early life depression. Evidence suggests that a variety of vascular mechanisms, in particular cerebral small vessel disease, generalized microvascular, and endothelial dysfunction, as well as metabolic risk factors, including diabetes, and inflammation that may induce subcortical white and gray matter lesions by compromising fronto-limbic and other important neuronal networks, may contribute to the development of LLD. The "vascular depression" hypothesis postulates that cerebrovascular disease or vascular risk factors can predispose, precipitate, and perpetuate geriatric depression syndromes, based on their comorbidity with cerebrovascular lesions and the frequent development of depression after stroke. Vascular burden is associated with cognitive deficits and a specific form of LLD, vascular depression, which is marked by decreased white matter integrity, executive dysfunction, functional disability, and poorer response to antidepressive therapy than major depressive disorder without vascular risk factors. Other pathogenic factors of LLD, such as neurodegeneration or neuroimmune regulatory dysmechanisms, are briefly discussed. Treatment planning should consider a modest response of LLD to antidepressants, while vascular and metabolic factors may provide promising targets for its successful prevention and treatment. However, their effectiveness needs further investigation, and intervention studies are needed to assess which interventions are appropriate and effective in clinical practice.

Age-Related Alterations in the Behavior and Serotonin-Related Gene mRNA Levels in the Brain of Males and Females of Short-Lived Turquoise Killifish (Nothobranchius furzeri)

Short-lived turquoise killifish (Nothobranchius furzeri) have become a popular model organism for neuroscience. In the present paper we study for the first time their behavior in the novel tank diving test and the levels of mRNA of various 5-HT-related genes in brains of 2-, 4- and 6-month-old males and females of N. furzeri. The marked effect of age on body mass, locomotor activity and the mRNA level of Tph1b, Tph2, Slc6a4b, Mao, Htr1aa, Htr2a, Htr3a, Htr3b, Htr4, Htr6 genes in the brains of N. furzeri males was shown. Locomotor activity and expression of the Mao gene increased, while expression of Tph1b, Tph2, Slc6a4b, Htr1aa, Htr2a, Htr3a, Htr3b, Htr4, Htr6 genes decreased in 6-month-old killifish. Significant effects of sex on body mass as well as on mRNA level of Tph1a, Tph1b, Tph2, Slc6a4b, Htr1aa, 5-HT2a, Htr3a, Htr3b, Htr4, and Htr6 genes were revealed: in general both the body mass and the expression of these genes were higher in males. N. furzeri is a suitable model with which to study the fundamental problems of age-related alterations in various mRNA levels related with the brains 5-HT system.