Loneliness affects memory in older adults but does not accelerate brain decline, finds study

Loneliness affects the memory of older adults but does not speed up mental decline over time, suggests data from a major European study tracking more than 10,000 people over seven years.

Participants who reported high levels of loneliness performed worse on memory tests at the start of the research period. However, the ability of lonely people to recall information declined at a similar rate over the timecourse monitored as that of participants who did not feel alone.

The findings, published in the peer-reviewed journal Aging & Mental Health, come from an analysis of the Survey of Health, Ageing and Retirement in Europe (SHARE) study, which

surveyed 10,217 people, aged 65 to 94, from 12 countries across the continent.

Loneliness has become a significant public health issue due to its impact on longevity, mental and physical health, and wellbeing.

These results add further weight to the strong links between feeling lonely and brain function in older people, while reinforcing the theory that isolation is not necessarily a risk factor for dementia.

Regular loneliness screening could be included in checks to test mental abilities in older adults, suggest the authors who are from the Universidad del Rosario in Colombia, the Clínica Universitaria de Navarra and Universitat de Valencia in Spain, and the Karolinska Institute in Sweden. They add that this approach could be one of several strategies that health professionals could develop to promote optimal ageing.

“The finding that loneliness significantly impacted memory, but not the speed of decline in memory over time was a surprising outcome,” says lead author Dr Luis Carlos Venegas-Sanabria, from the School of Medicine and Health Sciences at the Universidad del Rosario.

“It suggests that loneliness may play a more prominent role in the initial state of memory than in its progressive decline.

“The study underscores the importance of addressing loneliness as a significant factor in the context of cognitive performance in older adults.”

Loneliness and social isolation are among the most relevant risk factors for dementia. However, data on the link between loneliness and cognitive function are inconsistent. Some studies suggest loneliness accelerates cognitive decline over time while others have found no significant link.

The aim of this research was to assess the effect of loneliness on how memory changes over a seven-year period, namely immediate and delayed recall.

The analysis used data covering 2012 to 2019 from SHARE – a longitudinal survey launched in 2002 that examines the health and aging of Europeans aged 50 and over.

Participants included those from countries such as Germany, Spain, Sweden and Slovenia. All 12 countries were grouped into four geographic regions: Central, South, North and Eastern.

Anyone with a history of dementia including Alzheimer’s disease was excluded along with those whose activities related to daily living were ‘impaired’ (which was classified as people who have any disability in activities such as walking, eating, or taking a shower).

Memory was assessed as the ability to recall information immediately and after a time delay. Tests included participants having to remember as many words as possible in a minute. This was from a 10-word list which was read aloud.

Loneliness was defined as ‘feeling alone’. Researchers asked participants three questions to measure their loneliness and to categorise them into low, average or high.

The questions were as follows: How much of the time do you feel you lack companionship?, How much of the time do you feel left out?, and How much of the time do you feel isolated from others?

Researchers also assessed physical activity, engagement in social activities, depression scores, diabetes and other factors which could potentially influence the research.

Results showed Southern European countries reported the highest levels of loneliness (12%) followed by the Eastern region (9%), Central (6%) and Northern (9%) regions.

Overall, the majority of participants (92%) reported either average or low levels of loneliness at the start of the research. The group with high levels (8%) was older, mostly female and self-reported worse health issues. In addition, they had a higher prevalence of depression, high blood pressure and diabetes.

Those in the high category had lower immediate and delayed recall scores at the beginning of the study compared to those with lower loneliness levels.

However, they experienced a rapid decline in memory similar to that of participants in the low and average loneliness categories. This steep ‘slope’ was observed between the assessments at year three and year seven.

The authors highlight that their research treated loneliness as something that did not change over time. However, they say that in the real-world perceptions of loneliness can change ‘in response to shifts in personal or environmental characteristics across the lifespan’.

Reference:

Venegas-Sanabria, L. C., Pineda-Mateus, E., Borda, M. G., Satorres, E., Bueno-López, C., & Mélendez, J. C. (2026). Memory trajectories in lonely individuals in Europe: an analysis of the Survey of Health, Aging, and Retirement in Europe (SHARE). Aging & Mental Health, 1–10. https://doi.org/10.1080/13607863.2026.2624569