Late-Life Depression, Mild Cognitive Impairment, and Dementia: Possible Continuum?

Department of Geriatrics, Center for Aging Brain, Memory Unit, University of Bari, Bari, Italy.
The American journal of geriatric psychiatry: official journal of the American Association for Geriatric Psychiatry (Impact Factor: 4.24). 02/2010; 18(2):98-116. DOI: 10.1097/JGP.0b013e3181b0fa13
Source: PubMed


Clinical and epidemiologic research has focused on the identification of risk factors that may be modified in predementia syndromes, at a preclinical and early clinical stage of dementing disorders, with specific attention to the role of depression. Our goal was to provide an overview of these studies and more specifically to describe the prevalence and incidence of depression in individuals with mild cognitive impairment (MCI), the possible impact of depressive symptoms on incident MCI, or its progression to dementia and the possible mechanisms behind the observed associations. Prevalence and incidence of depressive symptoms or syndromes in MCI vary as a result of different diagnostic criteria and different sampling and assessment procedures. The prevalence of depression in individuals with MCI was higher in hospital-based studies (median: 44.3%, range: 9%-83%) than in population-based studies (median: 15.7%, range: 3%-63%), reflecting different referral patterns and selection criteria. Incidence of depressive symptoms varied from 11.7 to 26.6/100 person-years in hospital-based and population-based studies. For depressed normal subjects and depressed patients with MCI, the findings on increased risk of incident MCI or its progression to dementia were conflicting. These contrasting findings suggested that the length of the follow-up period, the study design, the sample population, and methodological differences may be central for detecting an association between baseline depression and subsequent development of MCI or its progression to dementia. Assuming that MCI may be the earliest identifiable clinical stage of dementia, depressive symptoms may be an early manifestation rather than a risk factor for dementia and Alzheimer disease, arguing that the underlying neuropathological condition that causes MCI or dementia also causes depressive symptoms. In this scenario, at least in certain subsets of elderly patients, late-life depression, MCI, and dementia could represent a possible clinical continuum.

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Available from: Francesco Panza, Mar 03, 2014
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    • ", 1997 ; Reynolds et al . , 2006 ; Unützer , 2007 ) . After many years of research , LLD is now con - sidered a multifactorial mood disorder , probably underpinned by several different mechanisms . It has variably been related to vascular disease , neurodegeneration , inflammatory processes and other age - related changes ( Nelson et al . , 2013 ; Panza et al . , 2010 ; Richard et al . , 2013 ) . Furthermore , LLD is still under - recognized and undertreated ; and the outcomes of LLD are broad , including the degree of treatment response ( Ellison et al . , 2012 ; Rojas - Fernandez et al . , 2010 ; World Economic Forum , 2011 ) ."
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    • "Cognitive impairment and depression are two common age-related syndromes, each of which present in approximately a quarter of the elderly population (Bennett and Thomas, 2014, Enache et al., 2011, Marazziti et al., 2010, Potter and Steffens, 2007). While exclusion criteria render problematic the estimation of the comorbidity of depression and cognitive impairment (Huang et al., 2011, Korczyn and Halperin, 2009, Weisenbach et al., 2012), several studies have established depression as a risk factor for cognitive impairment and the development of dementia with age (Gabryelewicz et al., 2007, Katon et al., 2010, Panza et al., 2010). Moreover, the most recent studies convincingly demonstrated objectively measurable deficits in key cognitive functions in a large proportion of patients in the midst of a major depressive episode (Papakostas, 2014, Trivedi and Greer, 2014), for review see (Marazziti, et al., 2010). "
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    Neurobiology of Aging 02/2015; 36(5). DOI:10.1016/j.neurobiolaging.2015.02.015 · 5.01 Impact Factor
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    • "This is in agreement with previous studies that showed that subjects with mild cognitive impairment and dementia have a higher incidence of depression (Weyerer et al., 2013; Arbus et al., 2011). Depression and cognitive disorders in the elderly share many risk factors and neurobiological abnormalities, and they probably have a bidirectional relationship (Butters et al., 2008; Panza et al., 2010). Interventions aiming the prevention and treatment of these conditions may significantly reduce the burden and risks related to these disorders. "
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