Further Evidence of Peripheral Inflammatory Markers Involvement in Late-Onset Depression and Cognitive Decline

Inflammation has been consistently associated with the pathophysiology of a series of neuropsychiatric disorders. 1 Bauer ME Teixeira AL. Inflammation in psychiatric disorders: what comes first?. Ann N Y Acad Sci. 2019; 1437: 57-67 Crossref PubMed Scopus (181) Google Scholar Increased brain and peripheral (i.e., serum or plasma) levels of pro-inflammatory cytokines are found in adults with mood disorders, and this knowledge has prompted the investigation of these molecules as potential biomarkers. For instance, alterations in peripheral cytokine levels have been associated with antidepressant treatment outcomes in major depression. 2 Liu JJ Wei YB Strawbridge R et al. Peripheral cytokine levels and response to antidepressant treatment in depression: a systematic review and meta-analysis. Mol Psychiatry. 2020; 25: 339-350 Crossref PubMed Scopus (139) Google Scholar More recently, peripheral inflammation (e.g., increased C reactive protein levels) has also been associated with micro-structural and functional connectivity changes in depression-related brain networks. 3 Kitzbichler MG Aruldass AR Barker GJ et al. Neuroimmunology of Mood Disorders and Alzheimer's Disease (NIMA) Consortium, Bullmore ET, Harrison NA. Peripheral inflammation is associated with micro-structural and functional connectivity changes in depression-related brain networks. Mol Psychiatry. 2021; (Epub ahead of print. PMID: 34535766)https://doi.org/10.1038/s41380-021-01272-1 Crossref PubMed Scopus (9) Google Scholar Risk of Late-Onset Depression and Cognitive Decline: Results From Inflammatory Proteome Analyses in a Prospective Population-Based Cohort StudyThe American Journal of Geriatric PsychiatryVol. 30Issue 6PreviewLate-onset depression (LOD), a depressive episode occurring for the first time in adults aged 65 years or older, is one of the most common neuropsychiatric disorders among older people.1-3 It has distinctive clinical features differentiating it from other types of depressive disorders, such as recurrent and early-onset depression4, and it has partially overlapping signs and symptoms with mild behavioral impairment5,6 and early-stage dementia.7-9 While distinctive clinical features raise the question of whether different types of depressive disorders present different biological markers, common clinical profiles between LOD and cognitive decline in old age raise the question of whether these two conditions share common biological underpinnings or whether, despite similar clinical presentations, biological markers can discriminate among pathologies with overlapping clinical profiles. Full-Text PDF