A positive attitude may go a long way toward reducing the likelihood of developing dementia, according to new research.
“This is one of the strongest studies I’ve seen on dementia and optimism,” says Davide Cappon, PhD, a psychologist and director of neuropsychology at Tufts Medical Center. “It helps answer a big ‘chicken-or-egg’ question, suggesting lack of optimism isn’t just an early symptom of dementia — it may actually be linked to risk in a more meaningful, potentially upstream way.”
Experts say the findings are especially exciting because people can train themselves to be more optimistic. Here’s what the research found, plus why this association might exist.
Noticeable Optimism May Protect the Brain
For the study, the researchers analyzed data from more than 9,000 people who participated in the Health and Retirement Study, a nationally representative sample of older American adults.
They gathered information on participants’ general life outlooks with a common 10-item questionnaire used to measure optimism versus pessimism. This was given at the start of the study, then again two years later. The researchers also tracked who went on to receive a dementia diagnosis during 14 years of follow-up.
Lead study author Säde Stenlund, MD, PhD, a research associate at the Harvard T.H. Chan School of Public Health, says that her team evaluated participants based on how they compared with someone with an average level of optimism.
After crunching the numbers, the researchers discovered that 1-standard deviation increase in optimism was linked with a 15 percent lower risk of developing dementia. “A 1-standard deviation increase is roughly the difference between someone with average optimism and someone who is noticeably more optimistic than average,” says Dr. Stenlund.
The researchers also conducted sensitivity analyses — modeling that looks at different variables — that suggested the association between optimism and lowered dementia risk was strong, and that it was not due to other factors like poor baseline mental health.
Low mood can be an early symptom of dementia, but the researchers found that the link between optimism and dementia was consistent, even when participants who developed dementia within the first two years were excluded from the study.
“These findings suggest a potential value of optimism in supporting healthy aging, which could be considered in future research on dementia prevention initiatives,” the researchers concluded.
How Attitude May Be Shaping Dementia Risk
Doctors say they’re not shocked by the association. “In my experience, optimistic people do better coping with their physical and mental health as they age,” says Cathryn Devons, MD, chief of geriatrics at Northwell’s Phelps Hospital in Sleepy Hollow, New York.
There are a few potential mechanisms behind this. “More optimistic people tend to engage in healthier behaviors, such as being more physically active, which is a known protective factor against dementia,” Stenlund says. “However, behavioral factors don’t seem to explain the majority of this relationship.”
Another potential contributing factor: Optimistic people are often better at managing stress, says Dr. Devons. “When you are optimistic, you are calmer,” she explains. “This will lower your blood pressure and decrease inflammation in your brain.” Optimism also decreases levels of the stress hormone cortisol in the brain — and elevated cortisol is another risk factor for memory loss, she says.
Being optimistic may engage your brain more, as well, says Clifford Segil, DO, a neurologist at Providence Saint John’s Health Center in Santa Monica, California. Although scientists have yet to find a clear “optimism pathway” in the brain, he says, staying optimistic requires higher-level brain functioning.
Finally, optimistic people are more likely to have strong social connections, which keeps the brain sharp, Stenlund says. “Biological pathways may play a role as well. For example, immune function is associated with both optimism and dementia and could be one mechanism underlying this association,” she says.
Optimism Is Teachable and Within Your Reach
Multiple doctors point out that optimism can be cultivated. “The encouraging part is that optimism isn’t fixed — it can be trained,” Dr. Cappon says. “There are randomized trials showing that optimism-focused interventions can lead to meaningful, sustained changes in biological markers, including those tied to cardiovascular health.”
These interventions usually involve strategies like mentally reframing challenges and practicing future-oriented thinking — imagining realistic, positive outcomes, as opposed to being pessimistic about what will happen, Cappon says. “On a day-to-day level, it can be as simple as keeping a gratitude habit, pausing to reset perspective in stressful moments, and staying socially connected,” he says.
To practice gratitude, Stenlund recommends writing down three things to be grateful for each day, which can help people foster a more positive view of the future, she says.
Dr. Segil also points out that adults shouldn’t overlook exercise when it comes to dementia prevention. “Keeping your brain and body busy are all good for brain health as we age,” he says.