Geriatric Depression and Cognitive Impairment—An Update

Abstract

Background: Depression and cognitive impairment often coexist in older adults. The relation between depression and cognitive impairment is complex. The objective of this article is to review recent literature on cognitive impairment in older adults with depression and provide clinicians an update. Methods: We searched PubMed, Google Scholar, Science Direct, and Psych Info for the articles published in the English language related to late-life depression (LLD)/geriatric depression and cognitive impairment. We considered original research articles, relevant systematic reviews, chapters, and important conceptual articles published in the last 9 years (2011–2019). We selected relevant articles for this narrative review. Conclusion: The concept pseudodementia, indicating depression with cognitive impairment mimicking dementia, is now seen only as a historical concept. The current literature strongly agrees with fact that cognitive deficits often exist in LLD. The cognitive deficits in depression were initially seen as trait marker; however, some recent studies suggest that cognitive deficits persist even in the remission phase. There is heterogeneity among the studies in terms of the nature of the cognitive deficits, but higher number of studies reported impairment in attention and executive function. LLD with cognitive deficits is at a higher risk of progression to dementia. In older adults, depression with cognitive impairments requires a comprehensive evaluation. Electroencephalography, event-related potentials, fluorodeoxyglucose–positron emission tomography, amyloid positron emission tomography, and CSF amyloid will supplement clinical evaluation in differentiating functional depressive disorder with cognitive impairment from depression with an underlying degenerative condition.

Incidence of cognitive impairment after hypothetical interventions on depression, nighttime sleep duration, and leisure activity engagement among older Chinese adults: An application of the parametric g-formula

“…The results of the present study showed that independent hypothetical interventions on depression, NSD, and IA could reduce cognitive impairment risks by 4.33%, 4.79%, and 9.94%, respectively, while the joint hypothetical intervention of all three factors could significantly reduce cognitive impairment risk by 17.11%. These findings confirmed the conclusions of earlier studies, wherein depression, inappropriate NSD, and limited IA were found to be risk factors for cognitive impairment among older adults ( 11 – 13 ). As the g-formula is a causal-effect analytic method, the results of the present study showed the causal effects of depression, inappropriate NSD, and limited IA engagement on the incidence of cognitive impairment.…”

“…As regards education, a Chinese-based longitudinal study revealed that a low education level is associated with a high risk of cognitive impairment among older adults ( 5 ). As well as gender and education level, depression, inappropriate nighttime sleep duration (NSD), and limited leisure activity engagement are reported as other risk factors for cognitive impairment among older adults ( 11 – 13 ). Obvious issues with addressing the immutable characteristic of gender, and difficulty with changing the education level, especially in older adults, are prevalent.…”

The Association of Adherence to the Mediterranean Diet with Depression in Older Adults Longitudinally Taking into Account Cognitive Status: Results from the HELIAD Study

“…A recent meta-analysis found that the prevalence of depression in older adults is around 28% [ 36 ]. In any case, it is well known that individuals with depression have compromised cognitive health [ 37 , 38 ] and that the prevalence of depression in older people having cognitive impairment is higher compared with those having normal cognitive functions [ 11 , 12 ]; however, it is not known whether depression is a risk factor for compromised cognitive health or whether depression constitutes a part of the long preclinical phase of the disease. Additionally, keeping in mind that adherence to the MeDi is positively connected with cognitive health [ 13 , 14 ], it is of great importance cognitive function to be accounted for when exploring the connection of diet with depression.…”

Association between physical activity and mild cognitive impairment in community-dwelling older adults: Depression as a mediator

“…Data from a prospective cohort in China showed that middle-aged and older adults who are depressed at baseline have a more rapid decline in cognitive status and that timely and effective prevention and treatment can reduce the decline in cognitive function ( Yang et al, 2020 ). Depression and cognitive dysfunction often coexist in the same patient ( Mukku et al, 2021 ), and one study found that geriatric depression and Alzheimer’s disease share three neurobiological features including neurodegeneration, cerebrovascular dysfunction, and elevated levels of neuroinflammation ( Weisenbach et al, 2019 ).…”