Life-Course Timing of Family Bereavement and Cognitive Impairment in Midlife to Later Life.

To examine whether the timing of family member deaths across the life course is associated with cognitive impairment and dementia in midlife to later life. Using 20 years of longitudinal data (2000-2020) from the US Health and Retirement Study and competing risks models, we examined how age at the time of a parent's, child's, or spouse's death is associated with the onset of mid-to-later-life cognitive impairment with or without dementia. Among individuals who experienced family member deaths, losses occurring at younger ages were associated with higher risks of cognitive impairment than losses occurring at older ages. The association for parental and spousal death timing became statistically nonsignificant after adjustment for early-life and adult health factors, whereas associations for child death timing remained robust across model specifications. We found no evidence of racial/ethnic or gender differences in these patterns. Our study identifies timing of bereavement as an underrecognized determinant of cognitive aging and highlights earlier-life loss as a strategic target for prevention and intervention. (. Published online ahead of print October 1, 2026:e1-e10. https://doi.org/10.2105/AJPH.2026.308744).