Author Response: Association of Loneliness With 10-Year Dementia Risk and Early Markers of Vulnerability for Neurocognitive Decline

We greatly appreciate the comment on our findings.¹ It is true that the associations of loneliness and frailty with increased dementia risk raise important questions that merit further exploration. We have begun to explore this by examining these longitudinal associations in the HAALSI cohort, which is composed of predominantly Black older adults from rural South Africa.² Although associations of loneliness are identified with notable neuroanatomical measures (lower total cerebral volume and greater white matter injury) in our present study, this was a cross-sectional analysis and would benefit from further validation. The temporal relationships of these pathways are worth exploring further, especially given prior cross-sectional evidence from the Harvard Aging Brain Study identifying associations between greater levels of loneliness and greater accumulation of cortical amyloid and right entorhinal tau on PET imaging.^3,4 We agree that, in light of studies that continue to provide evidence that supports the relevance of these pathways, there needs to be further action against loneliness and social isolation through targeted interventions that address the psychosocial determinants of brain health.