Social determinants of late-life depression epigenetics

The association of FKBP5 gene polymorphism with genetic susceptibility to depression and response to antidepressant treatment- a systematic review

BACKGROUND

Given the inconsistencies in current studies regarding the impact of FKBP5 gene polymorphisms on depression, arising from variations in study methods, subjects, and treatment strategies, this paper provides a comprehensive review of the relationship between FKBP5 gene polymorphisms and genetic susceptibility to depression, as well as their influence on response to antidepressant treatment.

METHODS

Electronic databases were searched up to April 11, 2023, for all literature in English and Chinese on depression, FKBP5 gene polymorphisms, and antidepressant treatment. Data extraction and quality assessment were performed for key study characteristics. Qualitative methods were used to synthesize the study results.

RESULTS

A total of 21 studies were included, with the majority exhibiting average to moderate quality. Six SNPs (rs3800373, rs1360780, rs9470080, rs4713916, rs9296158, rs9394309) were broadly implicated in susceptibility to depression, while rs1360780 and rs3800373 were linked to antidepressant treatment sensitivity. Additionally, rs1360780 was associated with adverse reactions to antidepressant drug treatment. However, these associations were largely unconfirmed in replication studies.

CONCLUSIONS

Depression is recognized as a polygenic genetic disorder, with multiple genes contributing, each exerting relatively small effects. Future studies should explore not only multiple gene interactions but also epigenetic changes. Presently, research on FKBP5 in affective disorders remains notably limited, highlighting the necessity for further investigations in this domain.

The epigenetics of frailty

The conceptual change of frailty, from a physical to a biopsychosocial phenotype, expanded the field of frailty, including social and behavioral domains with critical interaction between different frailty models. Environmental exposures - including physical exercise, psychosocial factors and diet - may play a role in the frailty pathophysiology. Complex underlying mechanisms involve the progressive interactions of genetics with epigenetics and of multimorbidity with environmental factors. Here we review the literature on possible mechanisms explaining the association between epigenetic hallmarks (i.e., global DNA methylation, DNA methylation age acceleration and microRNAs) and frailty, considered as biomarkers of aging. Frailty could be considered the result of environmental epigenetic factors on biological aging, caused by conflicting DNA methylation age and chronological age.

Depressive and Biopsychosocial Frailty Phenotypes: Impact on Late-life Cognitive Disorders

 In older age, frailty is a detrimental transitional status of the aging process featuring an increased susceptibility to stressors defined by a clinical reduction of homoeostatic reserves. Multidimensional frailty phenotypes have been associated with all-cause dementia, mild cognitive impairment (MCI), Alzheimer's disease (AD), AD neuropathology, vascular dementia, and non-AD dementias. In the present article, we reviewed current evidence on the existing links among depressive and biopsychosocial frailty phenotypes and late-life cognitive disorders, also examining common pathways and mechanisms underlying these links. The depressive frailty phenotype suggested by the construct of late-life depression (LLD) plus physical frailty is poorly operationalized. The biopsychosocial frailty phenotype, with its coexistent biological/physical and psychosocial dimensions, defines a biological aging status and includes motivational, emotional, and socioeconomic domains. Shared biological pathways/substrates among depressive and biopsychosocial frailty phenotypes and late-life cognitive disorders are hypothesized to be inflammatory and cardiometabolic processes, together with multimorbidity, loneliness, mitochondrial dysfunction, dopaminergic neurotransmission, specific personality traits, lack of subjective/objective social support, and neuroendocrine dysregulation. The cognitive frailty phenotype, combining frailty and cognitive impairment, may be a risk factor for LLD and vice versa, and a construct of depressive frailty linking physical frailty and LLD may be a good dementia predictor. Frailty assessment may enable clinicians to better target the pharmacological and psychological treatment of LLD. Given the epidemiological links of biopsychosocial frailty with dementia and MCI, multidomain interventions might contribute to delay the onset of late-life cognitive disorders and other adverse health-related outcomes, such as institutionalization, more frequent hospitalization, disability, and mortality.

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.

Evaluation of DNA methylation in BDNF, SLC6A4, NR3C1 and FKBP5 before and after treatment with selective serotonin-reuptake inhibitor in major depressive disorder

Aim: To identify the DNA methylation status of related genes in major depressive disorder following selective serotonin-reuptake inhibitor treatment. Materials & methods: 45 patients with major depressive disorder and 45 healthy volunteers were considered experimental and control groups, respectively. High-resolution melting real-time PCR was implemented to evaluate DNA methylation. Results: After 100 days of selective serotonin-reuptake inhibitor treatment, methylation of promoter CpG sites of BDNF, NR3C1, FKBP5 and SLC6A4 was significantly reduced. Compared with before treatment, patients' Hamilton Depression Rating Scale scores were significantly reduced after selective serotonin-reuptake inhibitor treatment (p ≤ 0.0001). Conclusion: Based on the proven effect of antidepressants on DNA methylation and gene expression, these medications can improve the treatment process and reduce depression scores after treatment.

Design and protocol of the multimorbidity and mental health cohort study in frailty and aging (MiMiCS-FRAIL): unraveling the clinical and molecular associations between frailty, somatic disease burden and late life depression

BACKGROUND

To explore the mutual relationship between multimorbidity, mental illness and frailty, we have set-up the Multimorbidity and Mental health Cohort Study in FRAILty and Aging (MiMiCS-FRAIL) cohort. At the population level, multimorbidity, frailty and late-life depression are associated with similar adverse outcomes (i.e. falls, disability, hospitalization, death), share the same risk factors, and partly overlap in their clinical presentation. Moreover, these three variables may share a common underlying pathophysiological mechanism like immune-metabolic dysregulation. The overall objectives of MiMiCS-FRAIL are 1) to explore (determinants of) the cross-sectional and longitudinal relationship between multimorbidity, depression, and frailty among non-demented geriatric outpatients; 2) to evaluate molecular levels of senoinflammation as a broad pathophysiological process underlying these conditions; and 3) to examine adverse outcomes of multimorbidity, frailty and depression and their interconnectedness.

METHODS

MiMiCS-FRAIL is an ongoing observational cohort study of geriatric outpatients in Brazil, with an extensive baseline assessment and yearly follow-up assessments. Each assessment includes a comprehensive geriatric assessment to identify multimorbidity and geriatric syndromes, a structured psychiatric diagnostic interview and administration of the PHQ-9 to measure depression, and several frailty measures (FRAIL, Physical Phenotype criteria, 36-item Frailty Index). Fasten blood samples are collected at baseline to assess circulating inflammatory and anti-inflammatory cytokines, leukocytes' subpopulations, and to perform immune-metabolic-paired miRome analyses. The primary outcome is death and secondary outcomes are the number of falls, hospital admissions, functional ability, well-being, and dementia. Assuming a 5-year mortality rate between 25 and 40% and a hazard rate varying between 1.6 and 2.3 for the primary determinants require a sample size between 136 and 711 patients to detect a statistically significant effect with a power of 80% (beta = 0.2), an alpha of 5% (0.05), and an R² between the predictor (death) and all covariates of 0.20. Local ethical board approved this study.

DISCUSSION

Frailty might be hypothesized as a final common pathway by which many clinical conditions like depression and chronic diseases (multimorbidity) culminate in many adverse effects. The MiMiCS-FRAIL cohort will help us to understand the interrelationship between these variables, from a clinical perspective as well as their underlying molecular signature.

Late-onset depression is associated to age-related central auditory processing disorder in an older population in Southern Italy

The association between late-life depression (LLD) and age-related hearing loss (ARHL) was suggested by preliminary studies, but reliance on LLD subtypes may introduce significant bias. We examined the association between ARHL and LLD according to the age of onset (early-onset depression (EOD) and late-onset depression (LOD)). We investigated the association between ARHL and LLD diagnosed according to the Semi-structured Clinical Diagnostic Interview for DSM-IV-TR in 1749 Italian community-dwelling older subjects from the population-based GreatAGE Study, Southern Italy. Peripheral ARHL was assessed as a pure tone average (PTA) threshold > 40 dB hearing level in the better ear- and age-related CAPD as a score of < 50% to the Synthetic Sentences Identification with Ipsilateral Competitive Message (SSI-ICM) test. LLD amounted at 10.29% of the sample, subdivided in LOD (6.21%) and EOD (4.08%). Age-related CAPD tended to be higher in LOD (28.91%) than in EOD (19.05%). After accounting for covariates, LOD was tendentially associated to age-related CAPD, but not to peripheral ARHL. This trend was confirmed by the linear models in which LOD was significantly associated to worsen SSI-ICM percentages (odds ratio 2.38, 95% confidence interval 1.32-4.30, p = 0.004), but not to PTA values. In a fully adjusted model of LOD, the effect of the association between CAPD and LOD was explained by social dysfunction. LLD was not associated to peripheral ARHL. Age-related CAPD was associated to LOD, a form of depression with cognitive dysfunction hallmark. The ARHL assessment may be an important opportunity to prevent depressive disorders in later life, particularly for LOD.

Social Frailty in the COVID-19 Pandemic Era

Special attention and efforts to protect from or reduce health-related outcomes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus triggering coronavirus disease 2019 (COVID-19), should be applied in susceptible populations, including frail older people. In particular, the early death cases occurred primarily in older people with a frailty status, possibly due to a weaker immune system fostering faster progression of the viral infection. Frailty is an age-related multidimensional clinical condition defined as a non-specific state of vulnerability, identifying older people at increased risk of falls, institutionalization, hospitalization, disability, dementia, and death. Among frailty phenotypes, social frailty has been least studied. It considers the role of socioeconomic context as a vulnerability status later in life. COVID-19 does not affect all populations equally, and social inequalities contribute to drive the spread of infections. It was known that the perception of social isolation, e.g., loneliness, affects mental and physical health, but the implicated molecular mechanisms, also related to the immune system, and its associated cognitive and health-related sequelae, are poorly understood. The increasing psychological distress derived by prolonged exposure to stress due to the lockdown scenario, and the reduced sources of support, contributed to making heavy demands on personal resources, i.e., self-efficacy and interpersonal variables. So, perceived loneliness may be a factor associated with psychological distress and an outcome in itself. In the COVID-19 pandemic era, a correct assessment of social frailty may be essential in terms of the prevention of late-life neuropsychiatric disorders.

The Impact of COVID-19 Infection and Enforced Prolonged Social Isolation on Neuropsychiatric Symptoms in Older Adults With and Without Dementia: A Review

Background: The sudden and drastic changes due to the Coronavirus Disease 19 (COVID-19) pandemic have impacted people's physical and mental health. Clinically-vulnerable older people are more susceptible to severe effects either directly by the COVID-19 infection or indirectly due to stringent social isolation measures. Social isolation and loneliness negatively impact mental health in older adults and may predispose to cognitive decline. People with cognitive impairments may also be at high risk of worsening cognitive and mental health due to the current pandemic. This review provides a summary of the recent literature on the consequences of COVID-19, due to either viral infection or social isolation, on neuropsychiatric symptoms in older adults with and without dementia. Methods: A search was conducted in PubMed and Web of Science to identify all relevant papers published up to the 7th July 2020. Two independent assessors screened and selected the papers suitable for inclusion. Additional suitable papers not detected by literature search were manually added. Results: Fifteen articles were included: 8 focussed on the psychiatric symptoms caused by the COVID-19 infection and 7 investigated the impact of social isolation on older adults' neuropsychiatric symptoms. Four studies included older adults without dementia and 11 included patients with cognitive impairment mainly due to Alzheimer's disease. All studies found that different neuropsychiatric symptoms emerged and/or worsened in older adults with and without dementia. These changes were observed as the consequence of both COVID-19 infection and of the enforced prolonged conditions of social isolation. Cases were reported of viral infection manifesting with delirium at onset in the absence of other symptoms. Delirium, agitation and apathy were the symptoms most commonly detected, especially in people with dementia. Conclusion: The available evidence suggests that the COVID-19 pandemic has a wide negative impact on the mental well-being of older adults with and without dementia. Viral infection and the consequent social isolation to limit its spreading have a range of neuropsychiatric consequences. Larger and more robustly designed studies are needed to clarify such effects and to assess the long-term implications for the mental health of older adults, and to test possible mitigating strategies.