Effects of Future Subjective Expectations on Cognitive Decline and Dementia among Middle-Aged and Older Adults

This study investigated the impact of subjective expectations of the future (e.g., income, life expectancy, and national policies) on the onset of dementia and mild cognitive impairment by sex and age in middle-aged and older adults. The Korean Longitudinal Study of Aging (KLoSA) data from 2008 to 2020, comprising 4116 people above 45 years, were used. A time-series analysis and multiple panel logistic regression were conducted to highlight subjective expectation trends and their effect on dementia and mild cognitive impairment, respectively. Low subjective expectations of the future negatively affected cognitive impairment (total: odds ratio [OR] = 1.02, 95% confidence interval [CI] = 1.01-1.03) and dementia (total: OR = 1.05, 95% CI = 1.03-1.06), and those of national policies were the biggest risk factors for cognitive impairment (total: OR = 1.17, 95% CI = 1.12-1.22) and dementia (total: OR = 1.10, 95% CI = 1.07-1.13). Individuals about to retire and with low expectations of workability were more likely to develop cognitive impairment (total: OR = 1.03, 95% CI = 1.02-1.06). Subjective expectations of economic downturn also caused cognitive impairment, especially in women (OR = 1.04, 95% CI = 1.01-1.07) and early stage older adults (OR = 1.06, 95% CI = 1.02-1.10). Policymakers must consider the impact of changes in national policies and living environments on cognitive impairment and dementia in older adults.