Higher optimism may lower dementia risk in older adults

By Vijay Kumar MalesuReviewed by Susha Cheriyedath, M.Sc.Apr 9 2026

A large U.S. study found that older adults with higher optimism were less likely to develop dementia over time, pointing to a promising psychological factor that could help shape future healthy aging research.

Study: The Bright Side of Life: Optimism and Risk of Dementia. Image Credit: Orawan Pattarawimonchai / Shutterstock

In a recent study published in the Journal of the American Geriatrics Society, a group of researchers examined whether higher levels of optimism are associated with a reduced risk of developing dementia in older adults.

Optimism, Brain Health, and Dementia Background

What if a positive attitude could be linked to better brain health as you age? Nearly 57 million people in the world live with dementia, and this number is expected to rise sharply in the coming years. Although treatment options for dementia are still severely restricted, a shift is taking place towards understanding how psychological and lifestyle factors may help impact brain health.

Optimism, defined as the general expectation that good things will happen, has been linked to longer life and better physical health. Although emerging findings suggest links between optimism and better cognitive health, uncertainty persists about this relationship across populations.

Additional research is needed to define the possible relationship between optimism and dementia risk, as well as to evaluate whether optimism itself may play a role in healthier cognitive aging.

Older Adult Dementia Study Design

The research analyzed participants aged 50 and older from the Health and Retirement Study (HRS), a national cohort from the United States. Participants were followed up with telephone interviews, in-person visits, and mailed questionnaires every 2 years.

The analysis included 9,071 cognitively healthy participants aged 70 and older at baseline who completed measures of optimism and cognition within a two-year period.

The Life Orientation Test-Revised (LOT-R) was used to assess participants' optimism through six statements rated on a Likert scale. Participants could score between 6 and 36 points on the LOT-R, with higher scores indicating greater optimism.

Dementia status was determined using the Expert algorithm based on logistic regression, incorporating 17 indicators, including cognitive test performance, physical health, demographic factors, proxy-rated cognition when needed, and social engagement. Sensitivity analyses also used the Langa-Weir algorithm for validation.

Covariates included age, sex, race and ethnicity, education, depression measured using the Center for Epidemiologic Studies Depression Scale (CES-D8), chronic health conditions, smoking status, and physical activity. Cox proportional hazards models were applied to estimate hazard ratios for dementia risk.

Multiple imputation addressed missing data, and additional analyses tested robustness by excluding early dementia cases and individuals with severe depression.

Higher Optimism Linked to Lower Dementia Risk

The study followed 9,071 older adults with a mean age of 74 years over an average of 6.7 years, with some participants observed for up to 14 years. During this period, 3,027 individuals developed dementia, and individuals with higher optimism levels consistently had a greater probability of remaining dementia-free over time.

Optimistic individuals were significantly distinguished from less optimistic individuals in many ways. Participants who showed higher optimism had higher levels of education, were more physically active, and were less likely to smoke.

In addition, they had significantly fewer chronic illnesses and considerably lower rates of depression than individuals with low optimism. For example, only 3.4% of individuals in the top optimism group reported probable depression, compared to 20% of individuals in the lowest group. This finding further supports the relationship between psychological and overall health.

Statistical analyses revealed a clear and consistent association between optimism and dementia risk. Each one-standard-deviation increase in optimism (equivalent to 6 points on the scale) was associated with a 15% reduction in the hazard of developing dementia (hazard ratio = 0.85; 95% confidence interval: 0.82-0.88), even after adjusting for demographic factors, depression, and physical health conditions.

These findings remained stable when additional lifestyle factors such as smoking and physical activity were included.

A graded pattern was also observed: individuals with higher levels of optimism showed progressively lower dementia risk. Individuals in the highest quartile had approximately 36-43% lower risk depending on the model used, indicating a monotonic trend.

Subgroup analyses showed that the protective association of optimism was consistent across Non-Hispanic White and Non-Hispanic Black participants, suggesting that the association was similar in these two subgroups. Sensitivity analyses further strengthened confidence in the findings.

Excluding participants who developed dementia within 2 years did not change the results, reducing concerns about reverse causation; however, the observational design means reverse causation cannot be ruled out completely. 

Similarly, removing individuals with the highest depression scores or using an alternative dementia classification method yielded nearly identical estimates. 

Overall, results consistently showed that higher optimism is linked to a lower risk of dementia.

Optimism and Healthy Aging Implications

Long-term follow-up of older adults indicates that older adults who express optimistic attitudes are at a decreased risk for developing dementia, regardless of demography or method of analysis. This research demonstrates that optimism may be a key factor in promoting healthy aging and could represent a potentially relevant psychosocial factor in future dementia prevention research.

Supporting positive attitudes through behavioral and/or psychological interventions may warrant further study as a complementary strategy, but additional research, including experimental and mechanistic studies, is needed to determine whether increasing optimism can directly reduce dementia risk.