Importance: As a financial hardship, negative wealth shock has been implicated in some adverse health outcomes. However, associations between negative wealth shock and cognitive decline and dementia have not been examined.Objective: To investigate whether negative wealth shock was associated with cognitive decline and incident dementia among middle-aged and older US adults.Design, Setting, and Participants: The Health and Retirement Study (HRS) is a prospective cohort study conducted biennially among US adults older than 50 years. Data from the HRS from calendar years 1996 to 2020 were analyzed from July 1 to 31, 2023. The final sample included 8082 participants with complete data of interest.Exposures: Wealth status was quantified with questionnaires. Negative wealth shock was defined as a loss of 75% or more in total wealth over a 2-year period. Asset poverty was defined as zero or less total net wealth.Main Outcomes and Measures: Cognitive function was assessed with the modified Telephone Interview for Cognitive Status (TICS-m). Dementia status was determined with TICS-m scores and proxy assessment.Results: Among 8082 participants included (mean [SD] age, 63.7 [5.7] years; 4179 women [51.7%] and 3903 men [48.3%]; 1111 Black [13.7%], 6689 White [82.7%], and 282 other [3.5%]), 1441 developed incident dementia over a median follow-up time of 14 (IQR, 7-20) years. Compared with participants who had positive wealth without shock, those with negative wealth shock had accelerated cognitive decline (β coefficient, −0.014 [95% CI, −0.027 to −0.001]; P = .03) and increased risks of dementia (hazard ratio [HR], 1.27 [95% CI, 1.11-1.46]; P < .001). Higher dementia risks were also found in participants with asset poverty at baseline (HR, 1.61 [95% CI, 1.30-2.00]; P < .001). Associations were found in White participants (HR, 1.34 [95% CI, 1.14-1.58]; P < .001) and participants younger than 65 years (HR, 1.38 [95% CI, 1.13-1.68]; P = .001) but not in other races and ethnicities or those 65 years or older.Conclusions and Relevance: In this cohort study, negative wealth shock was associated with accelerated cognitive decline and elevated risks of dementia among middle-aged and older US adults, with modifications by age and ethnicity. These findings should be confirmed by further prospective and interventional studies.

INTRODUCTION: Although the multimorbidity–dementia association has been widely addressed, little is known on the long‐term trajectory of multimorbidity (TOM) in preclinical dementia.METHODS: Based on the Health and Retirement Study, burden of multimorbidity was quantified with the total number of eight long‐term conditions (LTC). Patterns of TOM before dementia diagnosis were investigated with mixed‐effects models.RESULTS: In 1752 dementia cases and 5256 matched controls, cases showed higher and faster increasing predicted number of LTC than controls, with a significant case–control difference from 20 years prior to dementia diagnosis. Larger increases in number of LTC during preclinical phase of dementia were found in White participants, females, those whose age at dementia onset was younger, and those who were less educated.DISCUSSION: Our findings emphasize the faster accumulation of multimorbidity in prodromal dementia than in natural aging, as well as effect modifications by age and sex.Highlights: TOM increased faster in prodromal dementia than in natural ageing. Patterns of TOM by dementia status diverged at 20 years before dementia diagnosis. Patterns of TOM were modified by age and sex.