Feeling Older and the Development of Cognitive Impairment and Dementia.

Subjective age is a biopsychosocial marker of aging associated with a range of outcomes in old age. In the domain of cognition, feeling older than one's chronological age is related to lower cognitive performance and steeper cognitive decline among older adults. The present study examines whether an older subjective age is associated with the risk of incident cognitive impairment and dementia. Participants were 5,748 individuals aged 65 years and older drawn from the Health and Retirement Study. Measures of subjective age, cognition, and covariates were obtained at baseline, and follow-up cognition was assessed over a 2- to 4-year period. Only participants without cognitive impairment were included at baseline. At follow-up, participants were classified into one of the three categories: normal functioning, cognitive impairment without dementia (CIND), and dementia. An older subjective age at baseline was associated with higher likelihood of CIND (odds ratio [OR] = 1.18; 1.09-1.28) and dementia (OR = 1.29; 1.02-1.63) at follow-up, controlling for chronological age, other demographic factors, and baseline cognition. Physical inactivity and depressive symptoms partly accounted for these associations. An older subjective age is a marker of individuals' risk of subsequent cognitive impairment and dementia.