Editors' Note: Association of Loneliness With 10-Year Dementia Risk and Early Markers of Vulnerability for Neurocognitive Decline

ABSTRACT

Dr. Salinas and colleagues examined the association of loneliness at baseline with 10-year all-cause dementia risk and early cognitive and neuroanatomic imaging markers of Alzheimer disease and related dementia (ADRD) vulnerability in 2,308 participants in the population-based Framingham study cohorts. They found that loneliness was associated with increased dementia risk, with the risk tripling in adults whose baseline risk would otherwise be fairly low on the basis of age and genetic risk and that loneliness was also associated with worse markers of ADRD vulnerability, implying a potential early pathogenetic role. In response, Dr. Daly notes that a similar association was seen between frailty and 10-year dementia risk. He suggests studying the relationship between longitudinal changes in loneliness and neuroanatomical or neuropathologic measures, and the relationship of loneliness to frailty. He also emphasizes the importance of taking action against loneliness in society, which was aggravated by the COVID-19 pandemic especially among lower socioeconomic strata, to mitigate further social disparities in dementia risk. Responding to these comments, Dr. Salinas notes that the study team has begun exploring longitudinal associations of loneliness with dementia-related measures in another cohort, and points to compelling findings of greater cortical amyloid and entorhinal tau accumulation in patients with loneliness in the Harvard Aging Brain Study. Dr. Salinas echoes the need for interventions targeting loneliness and social isolation. This correspondence underscores our growing understanding of the role that psychosocial determinants of health play in the development of dementia. Although it seems clear that a social brain fares better than a lonely one over time, the question remains as to whether the lonely brain can be "rescued" by social interventions.