The study, published in the journal Neurology, found after factoring in for other dementia risk factors such as high blood pressure, high cholesterol and smoking, people with high levels of cynical distrust were three times more likely to develop dementia than people with low levels of cynicism.
Study author Anna-Maija Tolppanen of the University of Eastern Finland in Kuopio, said the study involved 1,449 people with an average age of 71, who were given tests for dementia and a questionnaire to measure their level of cynicism. The cynicism tests made participants rate their degree of agreement with statements such as: "I think most people would lie to get ahead," "It is safer to trust nobody," and "Most people will use somewhat unfair reasons to gain profit."
"These results add to the evidence that people's view on life and personality may have an impact on their health," Tolppanen said in a statement.
"Understanding how a personality trait like cynicism affects risk for dementia might provide us with important insights on how to reduce risks for dementia."
A total of 622 people completed two tests for dementia -- one at the beginning of the study and another eight years later on average. Forty-six people were diagnosed with dementia.