Memory trajectories in lonely individuals in Europe: an analysis of the Survey of Health, Aging, and Retirement in Europe (SHARE)

Background: Loneliness and social isolation are two of the most relevant risk factors for cognitive decline and dementia. However, the effect on specified cognitive domains, such as memory, has not been studied. This study aimed to investigate the impact of loneliness on the trajectory of memory decline over a six-year period among older adults without prior cognitive impairment.Methods: Longitudinal analysis using data from waves 5, 6, and 8 of the Survey of Health, Ageing and Retirement in Europe (SHARE). A total of 10217 older adults aged 65 years and older participated in all three waves (waves 5, 6, and 8) of SHARE and had complete data on loneliness assessment at baseline (wave 5). Loneliness was assessed using the Revised UCLA Loneliness Scale at baseline. Immediate and delayed recall were measured using a 10-word list recall task at each wave. The effect of loneliness on memory trajectories was assessed through a multilevel growth modelling approach.Findings: Participants with high loneliness at baseline demonstrated significantly lower immediate and delayed recall scores than those with low or average loneliness. However, loneliness did not influence the rate of decline in memory scores over the follow-up period.Interpretation: Loneliness is associated with lower initial memory performance in older adults but does not accelerate the decline in memory function over time. These findings underscore the importance of addressing loneliness as a modifiable risk factor for cognitive health in older populations.