Pessimistic, anxious and depressed people may have a higher risk of dementia, U.S. 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, i.e., 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.

They all took the Minnesota Multiphasic Personality Inventory, a standard personality and life experience test, Geda 's team told a meeting of the American Academy of Neurology in Miami.

In 2004 the team interviewed the participants or family members.

Those who scored higher for anxiety and pessimism on the test were more likely, as a group, to have developed dementia by 2004, including Alzheimer's disease and vascular dementia.

This did not mean a person who is pessimistic could assume he or she has a higher risk of developing dementia.

"One has to be cautious in interpreting a study like this," Geda said.

"One cannot make a leap from group level data to the individual. Certainly the last thing you want to do is to say, 'Well, I am a pessimist; thus, I am doomed to develop dementia 20 or 30 years later,' because this may end up becoming a self-fulfilling prophecy."

And there is not any specific way to prevent dementia, although many studies have shown that a healthy diet, exercise, keeping active in other ways, doing puzzles and other activities lower the risk.

美国研究人员4月14日公布的一份研究报告显示，悲观、忧虑和情绪低落的人更容易在数十年后患老年痴呆等病症。

据路透社4月14日报道，这项研究的负责人，美国明尼苏达州梅约医学中心的神经精神病学家约纳斯·格达和他的同事们查看了3500名该中心附近的居民从1962年至1965年间的医疗记录。这些人都曾填写过明尼苏达州多项个性检查表（一项关于个性及生活经历的标准性测试）。

2004年，格达研究小组专门对这些人或他们的家人进行了相关调查。结果显示，那些在个性测试中悲观表现得分高的人在30年至40年之后出现痴呆的风险较之其他人要高出30％。另外，那些同时具有忧郁和悲观性格的人，其以后发生痴呆的风险也更大，要比常人高出40％。

报道说，痴呆是一种神经疾病，会影响人们的思考、讲话、记忆和行动过程。尽管有许多研究结果曾显示，健康的饮食、多做体育锻炼、保持积极心态、多做拼图游戏等活动可以降低患痴呆症的风险，但是目前还没有任何一种特效方法能够预防这种病症的发生。