Pessimistic, anxious and depressed people may have a higher risk of dementia, US researchers reported on Thursday. A study of a group of 3,500 people showed that those who scored high for pessimism on a standardized personality test had a 30 percent increased risk of developing dementia 30 to 40 years later. Those scoring very high on both anxiety and pessimism scales had a 40 percent higher risk, the study showed. "There appears to be a dose-response pattern, ie, the higher the scores, the higher the risk of dementia," Dr. Yonas Geda, a neuropsychiatrist at the Mayo Clinic in Rochester, Minnesota who led the study, said in a statement. Geda and colleagues looked at the medical records of 3,500 men and women who lived near the clinic between 1962 and 1965.