Persistent cynicism may be linked to dementia

Mistrust of other people may put you at higher risk for dementia, according to a new study published in the journal Neurology. The study looked at the impact cynicism may have on long-term cognitive health.

Cynicism is defined as the belief that people are generally motivated by their own self interest and promotion and cannot be trusted.

For the study on 1,449 people, researchers at the University of Eastern Finland in Kuopio administered tests to screen for dementia, as well as questionnaires to gauge each person's level of cynicism. Out of that number, 622 people completed two tests for dementia, with the second one eight years after the start of the study. The average age of study participants was 71.

When taking the cynicism questionnaire people responded to statements such as "I think most people would lie to get ahead" and "It is safer to trust nobody." After scoring the questionnaire participants were divided into groups of low, moderate and high levels of cynicism.

A total of 46 people were diagnosed with dementia in the eight years between taking the two questionnaires. After adjusting for factors such high blood pressure and cholesterol, the researchers found people with high levels of cynicism were three times more likely to develop dementia than those with low levels of cynicism. A total of 164 people were found to have high levels of cynicism and 14 of them developed dementia. However, only nine out of 212 people with low levels of cynicism developed dementia.

Higher levels of cynicism also appeared to be linked to early death. However, after adjusting for factors such as income, health problems and lifestyle habits such as smoking the researchers found the link to be tenuous. Even still, there are a number of studies that show cynicism does impact physical health. A study published in American Journal of Epidemiology found that cynicism increases one's risk for acute myocardial infarction.

Dr. Joe Verghese, a professor of neurology and chief of the division of geriatrics at Albert Einstein College of Medicine and Montefiore Medical Center, says the study provides insight into the early stages of dementia. Verghese, who was not involved in the study, said viewing cynicism in light of other personality changes -- such as sudden onset depression, anger and paranoia -- may help with the early diagnosis of dementia in some patients. He added that the study doesn't necessarily indicate that lifelong cynics are at higher risk for dementia.

"They need to replicate these results elsewhere," he told CBS News. "It would be worthwhile to look at what cynicism does to the brain -- does it cause inflammation or does it damage networks, can it shrink areas in the brain."