Loneliness in the older adults is linked to poor lower memory but does not appear to accelerate memory decline.

Results of a longitudinal, observational cohort study of 10,000 older adults showed that lonely individuals started with lower memory scores, but not a faster rate of cognitive decline over 6 years.

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

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

The study was published online on April 14 in Aging and Mental Health.

The Loneliness Epidemic

Roughly one third of older adults in the US reported feeling lonely or socially isolated, a widespread public health concern experts have described as an “epidemic” because of its tangible health consequences. Research links loneliness to a greater risk for anxiety, depression, stroke, dementia, and premature death.

Given mixed evidence on the relationship between loneliness and cognitive function, the investigators hypothesized that greater loneliness would be associated with both poorer initial memory performance and a steeper decline over time.

Drawing on data from the Survey of Health, Ageing and Retirement in Europe, investigators examined data from 10,217 older adults from 12 countries (mean age, 72 years; 55% women). The study excluded individuals with a history of dementia or functional impairment. The follow-up period was 6 years.

Loneliness was defined as feeling alone and scored from low to high using the UCLA Loneliness Scale. Immediate memory was assessed based on participants’ ability to remember as many words as possible from a 10-word list in a minute. For delayed recall, participants completed the same task after a 5-minute delay.

Multiple linear models were used to assess memory change over time, adjusting for covariates including demographic factors, physical activity, health status, depression scores, diabetes, and social activity.

At baseline, 7.7% of participants reported high levels of loneliness, 26.8% average loneliness, and 65.5% low loneliness. The mean immediate recall score was 5.4 (SD, 1.6), whereas the mean delayed recall score was 4.8 (SD, 2.0).

Risk Profile

Those who reported high levels of loneliness were older, mostly women, and more likely to have depression, high blood pressure, and diabetes.

At study outset those who were the loneliest scored significantly lower on both immediate recall (beta = -0.24; 95% CI, -0.33 to -0.14) and delayed recall tests (beta = -0.21; 95% CI, -0.33 to -0.10), than those with low or average loneliness.

However, the investigators noted that the “association between loneliness and baseline memory is lower than the effects of age, depression, perceived health status, physical activity, or engagement in social activities.”

Over time, the loneliest participants’ memory declined at a rate similar to that of peers who initially reported average or low loneliness, suggesting that loneliness may not be a key driver of long-term decline.

A steep decline in memory — which was not linked to loneliness status — occurred between 3 years and 7 years. In the adjusted models, age had the greatest effect on initial memory scores and change over time.

Venegas-Sanabria said the findings “underscore the importance of addressing loneliness as a significant factor in the context of cognitive performance in older adults.”

A key limitation of the research was that loneliness was modeled as a fixed variable, which may not capture real-world changes in perceived loneliness over time. Other limitations included missing data on education level and marital status, along with the potential for self-report bias.

The authors reported having no relevant conflicts of interest, and no funding has been received to develop this study.