Aging as a Context for the Role of Inflammation in Depressive Symptoms

Abstract

Inflammation has been implicated in the pathogenesis and maintenance of depressive symptoms. The role of inflammation in depressive symptomatology may be complex, varying within endophenotypes and across the lifespan. Aging is associated with myriad changes in the structure and function of the brain. Yet, little attention has been given to the role of inflammation in depressive symptoms within a lifespan developmental framework. In this study, we examined whether the association between inflammation and depressive symptom domains varied by age. Participants were a community sample of individuals (N = 2,077, Range = 30–84) who participated in the Biomarker projects of the MIDUS2, MIDUS Refresher, or the MIDJA study. Inflammation was indexed by two inflammatory markers consistently implicated in depressed individuals, interleukin 6 (IL-6) and C-reactive protein (CRP), measured in blood. Depressive symptom domains, including depressed affect, anhedonia, somatic complaints, and interpersonal problems, were reported via the Center for Epidemiologic Studies—Depression Scale (CES-D). Inflammatory markers were associated with more somatic complaints, more interpersonal problems, and less anhedonia. Age moderated the relationship between inflammatory markers and two depressive symptom subscales. Specifically, the positive association between inflammation and somatic complaints and the negative association between inflammation and anhedonia increased with age. These observations offer preliminary evidence from a large community sample that aging may be an important context for the role of inflammatory signaling in different aspects of psychological and behavioral well-being.

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

“…IL-6 not only reduces the concentration of serotonin, but also damages the plasticity of synaptic nerves, which consequently results in cognitive impairment in LLD (51). Moreover, complaints and anhedonia, two important symptoms of depression, were positively correlated with C-reactive protein levels in patients with LLD, further supporting the link between inflammation and LLD (52).…”

Antioxidant Intervention to Improve Cognition in the Aging Brain: The Example of Hydroxytyrosol and Resveratrol

“…More precisely, age-related brain deterioration results in a scaffolding of new compensatory networks, depending on the factors that positively and negatively influence cognition. This decline is mostly associated with a dysfunction of the pre-frontal cortex, which, being especially vulnerable, tends to atrophy prematurely while aging, causing a reorganization of brain functioning, which often occurs with hemispheric lateralization of the solicited regions with more frequent bilateral brain activation [ 8 , 9 , 10 ]. Furthermore, many pathologies, such as common comorbidities in elder people, negatively affect cognition, though further studies are required to better understand how aging plays a role and how brain structure and brain function might mediate the relationship between comorbidities and age on cognition [ 11 , 12 , 13 ].…”

Synergistic associations of depressive symptoms and aging on cognitive decline in early Parkinson’s disease

“…In contrast, depression that begins around or after the age of 60 year (i.e., late-onset depression) is hypothesized to be a contributor to, or result of, accelerated brain and cognitive aging and both major and minor depression in older adults increases the risk of cognitive decline and conversion to dementia [ 34 ]. This may be due to both depression and aging having combined adverse effects on similar neural networks [ [35] , [36] , [37] ], neurotransmitter functions [ 38 ], and other biological processes (e.g., vascular changes, neuroinflammation) [ [39] , [40] ].…”