Change in Purpose in Life before and after Onset of Cognitive Impairment

Abstract

Importance: Purpose in life is a critical aspect of psychological well-being that is associated with better cognitive outcomes across the continuum of dementia. To our knowledge, the natural history of purpose with onset of cognitive impairment has yet to be evaluated. Objective: To evaluate changes in purpose in life prior to and after onset of cognitive impairment. Design, Setting, and Participants: This cohort study used assessments of purpose in life and cognitive status from March 2006 to May 2021 in the Health and Retirement Study (HRS) and from May 2011 to November 2021 in the National Health and Aging Trends Study (NHATS). Exposure: Cognitive impairment at each wave based on established thresholds in HRS and NHATS. Main Outcomes and Measures: The main outcome was purpose in life, measured with the Ryff Measures of Psychological Well-Being in HRS and a validated item in NHATS. Results: In HRS, 22668 participants provided 50985 assessments of purpose across all waves. In NHATS, 10786 participants provided 53880 assessments of purpose across all waves. In HRS, 58.3% of participants were female, with mean (SD) age of 64.76 (10.41) years at baseline; in NHATS, 57.4% were female, with mean (SD) age of 76.82 (7.71) years at baseline. Across waves, 6794 HRS participants (30%) and 4446 NHATS participants (41.2%) were in the cognitive impairment range. Accounting for demographic covariates and normative change in purpose, multilevel modeling indicated that standardized purpose in life declined significantly prior to onset of cognitive impairment (estimate for 10 years) in both HRS (b = -0.12; 95% CI, -0.17 to -0.07; P