Inter-connected trends in cognitive aging and depression: Evidence from the health and retirement study

The cohort process of cognitive aging is a contested topic in population research. The literature is largely in disagreement over how and why inter-cohort trends in cognitive aging occur in the United States. This paper examines significant trends in the rate of cognitive decline and conceptualizes the role of the depression trajectory as a late life course process that accelerates cognitive aging at the individual and population level. To this end, I draw my study sample from the Health and Retirement Study (N = 24,678) and use aging-vector models as an extension of parallel-process latent growth modeling to analyze repeated measures of cognition and depression. Findings show the acceleration of cognitive decline ("negative" Flynn Effect) and worsening of depression risk for recent cohorts. The upward trends in depression account for significant acceleration in cognitive decline among later cohorts, thus providing a new insight into socio-genic population dynamics of cognitive aging.