In the past decades, extensive research has aimed to identify risk factors, causative agent, treatments and preventive strategies for Alzheimer's disease (AD), the most common type of dementia. These efforts have predominantly focused on proximate behavioral and biological factors, but the upstream social determinants of cognitive decline and AD and related dementias (ADRD) are not well-understood. The overall objective of this proposed project is to ascertain how marriage, an important but overlooked social risk/protective factor, is linked to trajectories of cognitive decline and risk of developing dementia in late life. Marriage has long been identified as the most important type of social relationships that holds the greatest significance for health during adulthood. However, surprisingly, scientists know little about whether and how marriage influences cognitive decline and progression to ADRD. Rapid social changes in marriage, family formation, and family dissolution mean that an increasing number of older Americans are entering late life with complex marital histories, which reshapes key aspects of their lives, and may in turn affect cognitive function over the life course. We hypothesize that the complex life-course traits of marital relationships such as current marital status, histories of marital dissolutions, and marital strain, will influence trajectories of cognitive decline and dementia risk over one?s life course via multifaceted economic, psychosocial, behavioral, and biomedical pathways. This project breaks new ground with an innovative interdisciplinary life-course research design that conjoins data from three NIH-sponsored, national, longitudinal datasets: (1) Health and Retirement Study (HRS), (2) National Health and Aging Trends Study (NHATS), and (3) National Social Life, Health and Aging Project (NSHAP) to examine a full life course picture of marital relationships including marital status, marital biography and marital quality linked to cognitive trajectories and dementia. We will apply advanced statistical methods to systematically examine economic, psychosocial, behavioral and biomedical mechanisms through which marriage influences cognitive trajectories and dementia risk over the life course, and further assess potential gender differences in the processes. The interdisciplinary research team is characterized by a complementary set of talents and experience in population health, cognitive aging, marriage and social relationships, neurology, neuropsychology, bio-demography, epidemiology and quantitative methodologies that uniquely position them to carry out this innovative project.
This project aims to investigate the link of marriage with trajectories of cognitive decline and risk of developing dementia in late life using multiple nationally representative longitudinal datasets. Findings will contribute new knowledge that is critical for identifying the life-course social risk/protective factors of ADRD peculiar to marriage. Findings will also pinpoint the most vulnerable population segment at risk of ADRD, inform efforts to reduce ADRD-related healthcare cost, and yield insights enabling new public health strategies for optimizing cognitive health over the lifespan.
