Pessimists now have another reason to feel gloomy about the future. New research shows that people who are very pessimistic or anxious are more likely to develop dementia later in life.
"We speculate that pessimism makes people more susceptible to depression and other distressing emotions, which generate potentially toxic chemicals in the brain," says lead scientist Yonas Geda, a psychiatrist at the Mayo Clinic in Rochester, Minn.
Dementia is characterized by loss of cognitive abilities such as memory or reasoning, along with changes in personality. The disorder often occurs with other diseases, such as Alzheimer's and multiple sclerosis.
In the new study, researchers examined 3,500 Minnesota residents who had taken a personality test in 1962. Participants, who were 20 to 69 years old at the time of the test, were assessed for dementia or cognitive impairment in 2004.
Geda found that the higher a person had initially rated on the pessimism or depression scales, the more likely they were to later be diagnosed with dementia. "Those who rated in the top 25% of pessimists had a 30% increased risk for dementia," he says. A high anxiety score boosted the chance of dementia by an additional 10%.
The research was reported last week at the American Academy of Neurology meeting in Miami.