Aging
Hypothetical interventions on loneliness and memory function among middle-aged and older adults in the US Ryo Ikesu* Ryo Ikesu L. Paloma Rojas-Saunero Ashwin Kotwal Elizabeth Rose Mayeda
Background: Evidence has shown that people who experience persistent loneliness have lower memory function compared to those with transient loneliness or those who never feel lonely. However, it remains unclear whether sustained intervention on loneliness, as opposed to a one-time intervention, is more effective in preserving late-life memory function because no previous research has accounted for time-varying confounding for the association between loneliness and memory function. We aimed to examine the impact of sustained (two-time point) and one-time interventions of loneliness on memory function among middle-aged and older adults in the US.
Methods: Using the nationally-representative Health and Retirement Study in 2006–2016, we estimated the effects of [A] preventing loneliness at baseline and 4 years after baseline (sustained intervention at two time points) and [B] preventing loneliness only at baseline (one-time intervention) compared to natural course (i.e., no intervention) on memory scores 8 years after baseline. We used targeted maximum likelihood estimation to account for censoring and both baseline and time-varying confounding.
Results: The analytic sample included 16,977 participants (median baseline age, 68; 59% women). Compared to the natural course, both sustained and one-time interventions were associated with higher memory scores 8 years after baseline (0.026 standardized units [95% CI: 0.003–0.048] for the sustained intervention; 0.021 standardized units [95% CI: 0.005–0.037] for the one-time intervention).
Discussion: Our findings suggest that both sustained and one-time interventions on loneliness may be effective in preserving memory function. Future research is warranted to evaluate whether these interventions have differential impact on memory decline over a long period of follow-up.