Geroscience-Centric Perspective for Geriatric Psychiatry: Integrating Aging Biology With Geriatric Mental Health Research.

The geroscience hypothesis asserts that physiological aging is caused by a small number of biological pathways. Despite the explosion of geroscience research over the past couple of decades, the research on how serious mental illnesses (SMI) affects the biological aging processes is still in its infancy. In this review, we aim to provide a critical appraisal of the emerging literature focusing on how we measure biological aging systematically, and in the brain and how SMIs affect biological aging measures in older adults. We will also review recent developments in the field of cellular senescence and potential targets for interventions for SMIs in older adults, based on the geroscience hypothesis.

Late-Life Depression is Associated With Increased Levels of GDF-15, a Pro-Aging Mitokine.

OBJECTIVE: In older adults, major depressive disorder (MDD) is associated with accelerated physiological and cognitive aging, generating interest in uncovering biological pathways that may be targetable by interventions. Growth differentiation factor-15 (GDF-15) plays a significant role in biological aging via multiple biological pathways relevant to age and age-related diseases. Elevated levels of GDF-15 correlate with increasing chronological age, decreased telomerase activity, and increased mortality risk in older adults. We sought to evaluate the circulating levels of GDF-15 in older adults with MDD and its association with depression severity, physical comorbidity burden, age of onset of first depressive episode, and cognitive performance. DESIGN: This study assayed circulating levels of GDF-15 in 393 older adults (mean ± SD age 70 ± 6.6 years, male:female ratio 1:1.54), 308 with MDD and 85 non-depressed comparison individuals. RESULTS: After adjusting for confounding variables, depressed older adults had significantly higher GDF-15 serum levels (640.1 ± 501.5 ng/mL) than comparison individuals (431.90 ± 223.35 ng/mL) (t=3.75, d.f.= 391, p=0.0002). Among depressed individuals, those with high GDF-15 had higher levels of comorbid physical illness, lower executive cognitive functioning, and higher likelihood of having late-onset depression. CONCLUSION: Our results suggest that depression in late life is associated with GDF-15, a marker of amplified age-related biological changes. GDF-15 is a novel and potentially targetable biological pathway between depression and accelerated aging, including cognitive aging.

Neuroimaging features of depression-frailty phenotype in older adults: a pilot study.

OBJECTIVE: Frailty and late-life depression (LLD) often coexist and share several structural brain changes. We aimed to study the joint effect LLD and frailty have on brain structure. DESIGN: Cross-sectional study. SETTING: Academic Health Center. PARTICIPANTS: Thirty-one participants (14 LLD+Frail and 17 Never-depressed+Robust). MEASUREMENT: LLD was diagnosed by a geriatric psychiatrist according to the Diagnostic and Statistical Manual of Mental Disorders 5th edition for single episode or recurrent major depressive disorder without psychotic features. Frailty was assessed using the FRAIL scale (0-5), classifying subjects as robust (0), prefrail (1-2), and frail (3-5). Participants underwent T1-weighted magnetic resonance imaging in which covariance analysis of subcortical volumes and vertex-wise analysis of cortical thickness values were performed to access changes in grey matter. Participants also underwent diffusion tensor imaging in which tract-based spatial statistics was used with voxel-wise statistical analysis on fractional anisotropy and mean diffusion values to assess changes in white matter (WM). RESULTS: We found a significant difference in mean diffusion values (48,225 voxels; peak voxel: pFWER=0.005, MINI coord. (X,Y,Z) = -26,-11,27) between the LLD-Frail group and comparison group. The corresponding effect size (f=0.808) was large. CONCLUSION: We showed the LLD+Frailty group is associated with significant microstructural changes within WM tracts compared to Never-depressed+Robust individuals. Our findings indicate the possibility of a heightened neuroinflammatory burden as a potential mechanism underlying the co-occurrence of both conditions and the possibility of a depression-frailty phenotype in older adults.

Sex differences in dementia risk and risk factors: Individual-participant data analysis using 21 cohorts across six continents from the COSMIC consortium.

INTRODUCTION: Sex differences in dementia risk, and risk factor (RF) associations with dementia, remain uncertain across diverse ethno-regional groups. METHODS: A total of 29,850 participants (58% women) from 21 cohorts across six continents were included in an individual participant data meta-analysis. Sex-specific hazard ratios (HRs), and women-to-men ratio of hazard ratios (RHRs) for associations between RFs and all-cause dementia were derived from mixed-effect Cox models. RESULTS: Incident dementia occurred in 2089 (66% women) participants over 4.6 years (median). Women had higher dementia risk (HR, 1.12 [1.02, 1.23]) than men, particularly in low- and lower-middle-income economies. Associations between longer education and former alcohol use with dementia risk (RHR, 1.01 [1.00, 1.03] per year, and 0.55 [0.38, 0.79], respectively) were stronger for men than women; otherwise, there were no discernible sex differences in other RFs. DISCUSSION: Dementia risk was higher in women than men, with possible variations by country-level income settings, but most RFs appear to work similarly in women and men.

Increased Levels of Circulating Cell-Free mtDNA in the Plasma of Subjects With Late-Life Depression and Frailty: A Preliminary Study.

OBJECTIVE: To evaluate the circulating cell-free mitochondrial DNA (ccf-mtDNA) levels, a marker of cellular stress and damage, in older adults with late-life depression (LLD) and frailty. We hypothesize that individuals with both frailty and LLD will have higher ccf-mtDNA levels than individuals with either condition in isolation. METHODS: Fifty-three older adults (Never Depressed+Robust (reference group, n = 16), LLD+Robust (n = 9), Never Depressed+Prefrail/Frail (n = 5), and LLD+Prefrail/Frail (n = 23)) were included in the study. DNA was extracted from EDTA plasma samples, and ccf-mtDNA was quantified by RT-PCR. RESULTS: We found a statistically significant difference in the levels of ccf-mtDNA across groups (F(3,49) = 3.07, p = 0.036), with individuals in the LLD+Prefrail/Frail group showing the highest levels of ccf-mtDNA. CONCLUSION: The coexistence of LLD and frailty is associated with increased markers of cellular damage and stress (i.e., ccf-mtDNA). Our results suggest that these conditions may share cellular stress and mitochondrial dysfunction phenomena as a common biological mechanism, offering potential future opportunities for geroscience-guided interventions for these conditions.

Cognitive Frailty is Associated With Elevated Proinflammatory Markers and a Higher Risk of Mortality.

BACKGROUND: Cognitive impairment and physical frailty are common among older adults and associated with a higher likelihood of adverse health outcomes. These two conditions frequently coexist in the same individual as cognitive frailty, yet few studies have examined the impact of such comorbidity on clinical outcomes or underlying biological mechanisms. METHODS: A total of 1,340 older adults (age ≥60 years old) from the Bambui Cohort Study of Ageing, with a total follow-up of 10 years, were included in this study. Frailty was defined by the accumulation of deficit framework and cognitive impairment based on scores on the MMSE less than 22. In addition, serum IL-6 levels were measured by cytometric bead array assay. RESULTS: Individuals classified with cognitive frailty had significantly higher serum IL-6 levels compared to the robust, cognitively unimpaired group. Those with cognitive frailty (aOR = 1.97 [1.18-3.27] and prefrailty and cognitive impairment (aOR = 1.83 [1.24-2.69]) had the highest mortality risk over 10 years of follow-up. Higher IL-6 levels were also independently associated with a higher mortality rate (aOR = 1.37 [1.23-1.54]). CONCLUSION: Our study shows that cognitive Frailty indicates a vulnerability state and of increasing mortality risk. Our findings also suggested that proinflammatory abnormalities can be viewed as a central phenomenon underlying common age-related problems (e.g., cognitive impairment and Frailty) and outcomes (e.g., mortality).

Minocycline as adjunctive treatment for treatment-resistant depression: study protocol for a double blind, placebo-controlled, randomized trial (MINDEP2).

BACKGROUND: Available evidence suggests that adjunctive treatment with immunomodulatory medications may be effective in the treatment of major depressive disorder (MDD). A pilot trial of the tetracycline minocycline as adjunctive treatment in treatment-resistant depression (TRD), produced promising results, however, a larger scale trial is needed to confirm the antidepressant actions of this drug. METHODS: This is a 12-week double blind, placebo-controlled, randomized trial of minocycline as an add-on to standard antidepressants for adults (age > 18) with DSM-5 major depressive episode, who have failed to respond to at least two adequate trials of antidepressant treatment. It is a parallel-arm study with 50 participants in each group. The primary outcome measure is change in 17-item Hamilton Depression Rating Scale (HRSD-17) total scores from baseline to week 12. Secondary measures include the Clinical Global Impression (CGI) scale, World Health Organization Quality of Life Short Version (WHOQOL-BREF) and the Generalized Anxiety Disorder scale (GAD-7). Peripheral inflammatory biomarkers will be collected at baseline, week 6 and 12. DISCUSSION: If minocycline is well tolerated and effective in reducing depressive symptoms in patients with TRD, it would warrant genuine consideration as a treatment option for TRD. Additionally, if results demonstrate that minocycline has antidepressant properties, and that changes in inflammatory status are associated with its antidepressant action, it will inform the development of individualized treatment for a subset of patients with MDD. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT03947827. Registered 13th May, 2019.

Molecular Senescence Is Associated With White Matter Microstructural Damage in Late-Life Depression.

OBJECTIVES: The authors aim to investigate the association between white matter integrity and accelerated brain aging in late-life depression. METHODS: The authors measured senescence-associated secretory phenotype (SASP) index proteins, cognitive performance, and MRI diffusion tensor imaging (DTI) measures of fractional anisotropy and mean diffusivity-based indices of white matter microstructure measures in 56 older adults with remitted late-life depression. RESULTS: Higher SASP index was significantly correlated with older age (r = 0.42, p = 0.001) and worse executive function performance (r = -0.27, p = 0.04). After controlling for the effect of age, overall cognitive performance, and white matter hyperintensities, the association between SASP and left and right cingulate bundle mean diffusivity remained statistically significant. CONCLUSIONS: Our data suggest that, in the context of late-life depression, SASP proteins are associated with microstructural abnormalities in white matter tracts in brain and worse executive function performance.

Diabetes, depressive symptoms, and mortality risk in old age: The role of inflammation.

BACKGROUND: Both diabetes and depression increase the mortality risk in the elderly. In this study, we evaluated mortality risk associated with the comorbidity between depression and diabetes. We also assessed the moderating role of inflammation in the mortality risk in this population. METHODS: We included a total of 1,183 community-dwelling older adults, divided into four groups: "neither diabetes nor depression"; "diabetes only"; "depression only," and "both diabetes and depression," and followed-up for a median of 13.5 years. We evaluated the inflammatory status by the high-sensitivity C-reactive protein (hs-CRP) levels. Date of death was computed by reviewing death certificates. We used Cox's proportional hazards models and additive interactions to evaluate the risk of mortality in the subject groups and the moderating effect of hs-CRP. RESULTS: Participants with both diabetes and depression had higher death risk (hazard ratio [HR]: 2.33; 95% confidence interval [CI]: 1.59-3.42) than those with each condition alone (HR diabetes: 2.08 95% CI: 1.56-2.76 HR depression: 1.26; 95% CI: 1.03-1.54). High level of hs-CRP, indicative of high inflammatory status, significantly moderated the risk of mortality in subjects with both diabetes and depression (Bonferroni-adjusted p = 0.0116). CONCLUSIONS: The coexistence of diabetes and depression symptoms is associated with the highest death risk in this population. This risk is moderated by inflammatory status.

The Molecular Intersection Between Senescence and Major Depression in the Elderly.

Major depressive disorder in the elderly-or late-life depression (LLD)-is one of the most common mental illnesses in the aging population. LLD has several negative effects on health and well-being. Individuals with LLD have an elevated risk of chronic and persistent depressive symptoms as well as high rates of treatment resistance. They also have a higher risk of developing cognitive impairment with progression to dementia and higher rates of medical comorbidity, frailty, and mortality. The mechanisms linking LLD to these adverse health outcomes are not well understood. In this article, we review the evidence that individuals with LLD present with, i.e., enhanced molecular and cellular senescent changes, focusing on the senescence-associated secretory phenotype (SASP). We then propose a mechanistic model linking SASP to the greater risk of negative health outcomes in this population. We finally provide evidence that SASP-and cellular senescence in general-can be a therapeutic target for mitigating the risk of these negative outcomes in LLD.

The association between insulin resistance, metabolic variables, and depressive symptoms in Mexican-American elderly: A population-based study.

OBJECTIVE: Depressive symptoms are common among older adults with obesity and diabetes. Nonetheless, the mechanisms for this association are not clear but may involve changes in the insulin cascade signaling. We aimed to investigate the association, and potential mediators, between obesity, insulin resistance, and depressive symptoms among older adults from a homogenous cohort of Mexican-Americans. METHODS: We included a total of 500 Mexican-American older adults assessed in the Cameron County Health Study. We evaluated depressive symptoms using the Center for Epidemiologic Survey Depression Scale (CES-D). Central obesity was defined by waist circumference. Insulin resistance was evaluated by the HOMA-IR index. We estimated the association between obesity, insulin resistance, and depressive symptoms by carrying out univariate and multivariate regression analyses. RESULTS: In unadjusted regression analysis, HOMA-IR (unstandardized ß = 0.31 ± 0.12, P = 0.007), waist circumference (unstandardized ß = 0.066 ± 0.0.028, P = 0.017), and Hb1Ac levels (unstandardized ß = 0.52 ± 0.24, P = 0.03) were significantly associated with CES-D scores. The association of HOMA-IR and CES-D remained statistically significant after controlling for socio-demographic and clinical variables in multivariate analysis (unstandardized ß = 0.28 ± 0.11, P = 0.01). CONCLUSION: Our results suggest that depressive symptoms are associated with insulin resistance in older Mexican-American adults. In addition, poorer glucose control and obesity are important mediators of this relationship. Additional studies are needed to evaluate whether interventions that increase insulin sensitivity can also reduce depressive symptoms in this population.

The impact of substance use disorders on clinical outcomes in older-adult psychiatric inpatients.

OBJECTIVE: To examine associations among substance use disorder (SUD) and measures of length of stay (LOS) and non-psychiatric medical comorbidity (MEDCO) in older-adult inpatients with serious mental illness (SMI), hypothesizing SUD would be related to worse clinical outcomes. METHODS: A cross-sectional study analyzed medical records from 2010 to 2016 of 7258 inpatients with SMI ≥ age 50, obtained from a 274-bed psychiatric hospital. Descriptive analyses examined prevalence rates for SUD status (+/-), individual drug classes, and total number of SUDs (polysubstance use disorders). Regression models examined the influence of 2 independent variables of interest: (1) SUD status (+/-) and (2) type of SUD (ie, specific drug), controlling for demographic factors and additional (non-SUD) psychiatric disorders. Two dependent (outcome) variables were examined: LOS and MEDCO. RESULTS: The overall SUD rate was 26%; cocaine was the most common SUD (≈ 10%). SUD status and additional (non-SUD) psychiatric diagnoses were significantly associated with longer LOS (both P < 0.001). For individual SUDs, cocaine, marijuana, opiates, and alcohol were all significantly associated with LOS (all P < 0.01). SUD status, age, sex, admission status, and race were significantly associated with MEDCO (all P < 0.002). For individual SUDs, barbiturates, opiates, and alcohol were all significantly associated with MEDCO (P < 0.01). CONCLUSIONS: The prevalence of SUD in this sample underscores concerns related to treating older adults presenting providers with comorbid SUD and SMI. This combination may increase the burden and complexity of care, warranting further investigation into mechanisms and long-term consequences.

Potential Use of Stem Cells in Mood Disorders.

Mood disorders are heterogeneous conditions characterized by complex genetics, unclear pathophysiology, and variable symptomatology. Currently, there is no biomarker for the diagnosis or prognosis of mood disorders, and the treatments are of limited efficacy in a significant proportion of patients. Furthermore, the disease models are not able to recapitulate their complexity. In this scenario, stem cells may have different applications in mood disorders. Circulating stem cells may be regarded as potential biomarkers. Mesenchymal stem cells are a promising therapeutic strategy for mood disorders as they promote neurogenesis and increase the expression of neurotrophic factors that enhance the survival and differentiation of neurons. In addition, induced pluripotent stem cells, cells reprogrammed from somatic cells of healthy subjects or patients, offer a great opportunity to recapitulate both normal and pathological development of human brain tissues, thereby opening a new avenue for disease modeling and drug development in a more disease-relevant system.

History of Bipolar Disorder and the Risk of Dementia: A Systematic Review and Meta-Analysis.

OBJECTIVE: We carried out a systematic review and meta-analysis to evaluate whether history of bipolar disorder (BD) increases the risk of dementia. METHODS: We searched PubMed and Scopus to identify studies that evaluated the risk of dementia in individuals with a history of BD. A total of 6 studies including 3,026 individuals with history of BD and 191,029 non-BD individuals were included in the meta-analysis. RESULTS: History of BD significantly increased the risk of diagnosis of dementia (pooled odds ratio: 2.36; 95% confidence interval: 1.36-4.09; z = 3.07, p < 0.001). Evidence of heterogeneity and of publication bias in the analysis was found. CONCLUSION: History of BD is associated with significantly higher risk of dementia in older adults. Future studies are necessary to evaluate the potential mediators of this association and to evaluate interventions that may reduce the risk of dementia in this population.

Immunological biomarkers associated with brain structure and executive function in late-life depression: exploratory pilot study.

OBJECTIVE: Several immunological biomarkers are altered in late-life major depressive disorder (LLD). Immunological alterations could contribute to LLD's consequences, but little is known about the relations between specific immunological biomarkers and brain health in LLD. We performed an exploratory pilot study to identify, from several candidates, the specific immunological biomarkers related to important aspects of brain health that are altered in LLD (brain structure and executive function). METHODS: Adults (n = 31) were at least 60 years old and had major depressive disorder. A multiplex immunoassay assessed 13 immunological biomarkers, and we examined their associations with structural MRI (grey matter volume and white matter hyperintensity volume (WMH)) and executive function (Color-Word Interference and Trail-Making tests) measures. RESULTS: Vascular endothelial growth factor (VEGF) and the chemokine eotaxin had significant negative associations with grey matter volume (VEGF: n = 31, r = -0.65; eotaxin: n = 29, r = -0.44). Tumor necrosis factor alpha (TNF-α) had a significant positive relationship with WMHs (n = 30, r = 0.52); interferon-γ (IFN-γ) and macrophage inflammatory protein-1α (MIP-1α) were also significantly associated with WMHs (IFN-γ: n = 31, r = 0.48; MIP-1α: n = 29, r = 0.45). Only eotaxin was associated with executive function (set-shifting performance as measured with the Trail-making test: n = 33, r = -0.43). CONCLUSIONS: Immunological markers are associated with brain structure in LLD. We found the immunological correlates of grey and white matter differ. Prospective studies are needed to evaluate whether these immunological correlates of brain health increase the risk of LLD's consequences. Eotaxin, which correlated with both grey matter volume and set-shifting performance, may be particularly relevant to neurodegeneration and cognition in LLD. Copyright © 2016 John Wiley & Sons, Ltd.

Vascular depression consensus report - a critical update.

BACKGROUND: Vascular depression is regarded as a subtype of late-life depression characterized by a distinct clinical presentation and an association with cerebrovascular damage. Although the term is commonly used in research settings, widely accepted diagnostic criteria are lacking and vascular depression is absent from formal psychiatric manuals such as the Diagnostic and Statistical Manual of Mental Disorders, 5th edition - a fact that limits its use in clinical settings. Magnetic resonance imaging (MRI) techniques, showing a variety of cerebrovascular lesions, including extensive white matter hyperintensities, subcortical microvascular lesions, lacunes, and microinfarcts, in patients with late life depression, led to the introduction of the term "MRI-defined vascular depression". DISCUSSION: This diagnosis, based on clinical and MRI findings, suggests that vascular lesions lead to depression by disruption of frontal-subcortical-limbic networks involved in mood regulation. However, despite multiple MRI approaches to shed light on the spatiotemporal structural changes associated with late life depression, the causal relationship between brain changes, related lesions, and late life depression remains controversial. While postmortem studies of elderly persons who died from suicide revealed lacunes, small vessel, and Alzheimer-related pathologies, recent autopsy data challenged the role of these lesions in the pathogenesis of vascular depression. Current data propose that the vascular depression connotation should be reserved for depressed older patients with vascular pathology and evident cerebral involvement. Based on current knowledge, the correlations between intra vitam neuroimaging findings and their postmortem validity as well as the role of peripheral markers of vascular disease in late life depression are discussed. CONCLUSION: The multifold pathogenesis of vascular depression as a possible subtype of late life depression needs further elucidation. There is a need for correlative clinical, intra vitam structural and functional MRI as well as postmortem MRI and neuropathological studies in order to confirm the relationship between clinical symptomatology and changes in specific brain regions related to depression. To elucidate the causal relationship between regional vascular brain changes and vascular depression, animal models could be helpful. Current treatment options include a combination of vasoactive drugs and antidepressants, but the outcomes are still unsatisfying.

Shared Biologic Pathways Between Alzheimer Disease and Major Depression: A Systematic Review of MicroRNA Expression Studies.

OBJECTIVE: The clinical-epidemiological relationship between major depressive disorder (MDD) and Alzheimer disease (AD) suggests that they may share common neurobiologic abnormalities. METHODS: The authors conducted a systematic review and identified microRNAs abnormally expressed in both AD and MDD. The pattern of microRNA regulation in each disorder and the genes regulated by each microRNA and the biologic processes and pathways regulated by these genes were identified. RESULTS: Seventy-four microRNAs were abnormally expressed in AD and 30 in MDD; 7 were common for both disorders (hsa-let-7f-5p, hsa-miR-664a-3p, hsa-miR-361-5p, hsa-let-7g-5p, hsa-let-7d-5p, hsa-miR-191-5p, hsa-miR-26b-5p). These microRNAs interact with 45 validated genes, and the main biologic pathways and processes regulated by them were proteostasis control, maintenance of genomic integrity, regulation of transcriptional activity, immune-inflammatory control, and neurotrophic support. CONCLUSION: The current results suggest that the maintenance of genomic integrity, proteostasis control, immune-inflammatory regulation, and neurotrophic support are key neurobiologic links between these conditions. A comprehensive hypothetical model for the interaction between MDD, aging, and the development of AD is provided.