No Association Between Loneliness, Episodic Memory and Hippocampal Volume Change in Young and Healthy Older Adults: A Longitudinal European Multicenter Study

Abstract

BackgroundLoneliness is most prevalent during adolescence and late life and has been associated with mental health disorders as well as with cognitive decline during aging. Associations between longitudinal measures of loneliness and verbal episodic memory and brain structure should thus be investigated.MethodsWe sought to determine associations between loneliness and verbal episodic memory as well as loneliness and hippocampal volume trajectories across three longitudinal cohorts within the Lifebrain Consortium, including children, adolescents (N = 69, age range 10–15 at baseline examination) and older adults (N = 1468 over 60). We also explored putative loneliness correlates of cortical thinning across the entire cortical mantle.ResultsLoneliness was associated with worsening of verbal episodic memory in one cohort of older adults. Specifically, reporting medium to high levels of loneliness over time was related to significantly increased memory loss at follow-up examinations. The significance of the loneliness-memory change association was lost when eight participants were excluded after having developed dementia in any of the subsequent follow-up assessments. No significant structural brain correlates of loneliness were found, neither hippocampal volume change nor cortical thinning.ConclusionIn the present longitudinal European multicenter study, the association between loneliness and episodic memory was mainly driven by individuals exhibiting progressive cognitive decline, which reinforces previous findings associating loneliness with cognitive impairment and dementia.

Association between loneliness and its components and cognitive function among older Chinese adults living in nursing homes: A mediation of depressive symptoms, anxiety symptoms, and sleep disturbances

“…Our results showing an inverse association between loneliness and cognitive function are consistent with those of previous studies that found loneliness to be a risk factor for cognitive impairment [8,42]. However, several previous studies have failed to find a significant association between loneliness and cognitive function [9,18]; this difference may be related to the measurements used. In those studies, cognitive function was measured using the Mini-Mental State Examination [9], which is less sensitive than the MoCA in measuring the subtle cognitive decline in older people without dementia [43,44], or loneliness was measured using a single item [18], which Abbreviations: CI: confidence interval; Q: quartile a Adjusted for age, sex (male or female), education level (elementary or lower, junior high, senior high, college or higher), current smoking (yes or no), current drinking (yes or no), sitting (h/d), walking for more than 10 min at least one day in the last week (yes or no), moderate or vigorous activity (yes or no), marital status (married or widowed, divorced, or unmarried), living status (living alone, living with one roommate, living with two roommates, living with three roommates), overweight (yes or no), number of comorbidities, hearing impairments (yes or no) is prone to measurement error [45].…”

“…Our results showing an inverse association between loneliness and cognitive function are consistent with those of previous studies that found loneliness to be a risk factor for cognitive impairment [ 8 , 42 ]. However, several previous studies have failed to find a significant association between loneliness and cognitive function [ 9 , 18 ]; this difference may be related to the measurements used. In those studies, cognitive function was measured using the Mini-Mental State Examination [ 9 ], which is less sensitive than the MoCA in measuring the subtle cognitive decline in older people without dementia [ 43 , 44 ], or loneliness was measured using a single item [ 18 ], which is prone to measurement error [ 45 ].…”

“…However, several previous studies have failed to find a significant association between loneliness and cognitive function [ 9 , 18 ]; this difference may be related to the measurements used. In those studies, cognitive function was measured using the Mini-Mental State Examination [ 9 ], which is less sensitive than the MoCA in measuring the subtle cognitive decline in older people without dementia [ 43 , 44 ], or loneliness was measured using a single item [ 18 ], which is prone to measurement error [ 45 ]. In the present study, we used the MoCA to measure the total cognitive function, which is sensitive and can capture subtle cognitive decline [ 43 , 44 ].…”

“…Existing evidence on the association between loneliness and cognitive function has yielded mixed results, with some studies showing significant inverse associations between loneliness and its components and cognitive function [ 8 , 15 , 16 ], whereas others suggest no association [ 17 , 18 ]. In addition, to the best of our knowledge, few studies have investigated the association between the components of loneliness and cognitive function.…”

Longitudinal monitoring of the mouse brain reveals heterogenous network trajectories during aging

“…This has several disadvantages 2 and leads to a bias to exclude individuals that will develop cognitive symptoms early on 31 . Interestingly, human studies utilizing a longitudinal design 17 , 33 , 34 show a rather limited effect of sex on human brain aging.…”