Groiue 2010-3-18 11:51
生命目的可能降低阿茲海默氏症風險
作者：Allison Gandey
出處：WebMD醫學新聞
March 3, 2010 — 研究者們報告，有強烈生命目的意義的老年病患，發生阿茲海默氏症（AD）的風險低了將近2.5倍。
這項新發現與越來越多的研究數據顯示，精神和經驗性因子都與認知功能受損有關。
共同作者伊利諾州芝加哥Rush大學醫學中心的Lisa Barnes博士向Medscape精神醫學表示，我們的研究結果指出，正向因子，例如有指引行為目標導引性的感覺，可能提供對抗負面健康結果的緩衝劑，特別是在老年的時候。
她表示，由於潛在的公共衛生應用性，這些研究結果有其重要性。生命目的是我們確實可以在老年時做到的一些改變，透過提供高齡患者一些方法，讓他們可以在活動中找到意義、達到目的與目標。
這項研究發表在3月號的一般精神科學學誌。
【認知功能受損比較不容易受損】
研究者們進行了一項前瞻性、縱向、流行病學研究，收納超過900位居住於社區，沒有失智問題的成人。
該團隊由也在Rush大學任職的Patricia Boyle博士所領導，她評估生命的目的，並進行平均4年的詳細年度後續追蹤臨床評估。受試者們來自Rush記憶與老化計畫。
剛好超過16%的試驗參與者發生AD。在比例風險模式中校正年齡、性別與教育程度，研究者們發現較大的生命目的與疾病風險顯著下降有關。危險比值為0.48，95%信賴區間為0.33到0.69（P<0.001）。
在接下來的分析中，Boyle博士與他的團隊檢驗生命目的與輕微認知功能受損之間的關係；輕微認知受損是AD的臨床前表徵。
他們發現，生命的目的也與突發認知功能受損風險下降有關。危險比值為0.71，95%信賴區間為0.53-0.95（P=0.02）。
Barnes博士表示，我們無法建立因果關係，然而，在校正重要因子後，例如憂鬱症狀、神經質、社交網絡與慢性健康狀況數目後，我們發現生命目的可以預防阿茲海默氏症發生。在敏感度測試時，於後續追蹤的前三年依序排除發生阿茲海默氏症的病患，這個關係仍然持續。
Barnes博士解釋，這提起了一些擔憂，或許那些病患罹患了未被診斷的或是輕微的AD。
她表示，或許我們推論因果關係的能力有限，但這樣額外的校正強化了我們對於這些發現的信心。
【精神上的健康】
最近另外一項研究發現，生命目的的感覺是嚴重外傷後決定精神健康最重要的因子（Am J Psychiatry. 2008; 165: 1566-75）。
當這篇文章首次於11月在線上發表時，來自紐約市密蘇里醫學院的Adriana Feder醫師向Medscape精神學表示，我們發現，與恢復力或是恢復狀態有關之最重要的精神因子是較高的生命目的感覺。我們也發現，控制或是有控制一個人生命的強烈感覺與恢復狀態最有關係。
這項新研究據聞是第一項評估生命目的與AD風險的研究，但是研究者們已經對同一群病患評估其他健康預後，且觀察到死亡風險是下降的。
Barnes醫師表示，生命中的目的是人類欣欣向榮的一個指標，且已經被假設與神經上的健康有關。
這項研究由國家高齡化機構，伊利諾公共衛生部門與Robert C Borwell Endowment基金會贊助。研究者們表示沒有相關資金上的往來。
Purpose in Life May Reduce Alzheimer's Risk
By Allison Gandey
Medscape Medical News
March 3, 2010 — Elderly people with a strong sense of purpose in life are almost 2? times less likely to develop Alzheimer's disease (AD), report researchers.
The new finding adds to emerging data suggesting that psychological and experiential factors are associated with cognitive impairment.
"Our results suggest that positive factors, such as having a sense of goal-directedness that guides behavior, may provide a buffer against negative health outcomes, particularly in old age," coauthor Lisa Barnes, PhD, from the Rush University Medical Center, Chicago, Illinois, told Medscape Psychiatry.
"These results are important because of the potential public health implications," she noted. "Purpose in life is something we can actually modify in old age by giving older adults specific strategies they can use to find meaning in activities, achieve purposes, and goals."
The study is published in the March issue of the Archives of General Psychiatry.
Less Cognitive Impairment
Dr. Patricia Boyle
Investigators conducted a prospective, longitudinal, epidemiologic study of more than 900 community-dwelling, older people without dementia.
The group, led by Patricia Boyle, PhD, also at Rush University, evaluated purpose in life and a mean of 4 years of detailed annual follow-up clinical evaluations. Participants were from the Rush Memory and Aging Project.
Just more than 16% of the study population developed AD. In a proportional hazards model adjusted for age, sex, and education, investigators found that a greater purpose in life was associated with a substantially reduced risk for disease. The hazard ratio was 0.48, with a 95% confidence interval of 0.33 to 0.69 (P < .001).
In subsequent analyses, Dr. Boyle and her team examined the association of purpose in life with mild cognitive impairment, an early preclinical manifestation of AD.
They found that purpose in life also reduced the risk for incident cognitive impairment. The hazard ratio was 0.71, with a 95% confidence interval of 0.53 to 0.95 (P = .02).
"We cannot establish causality with certainty," Dr. Barnes said. "However, we found that purpose in life was protective against Alzheimer's disease even after adjusting for important factors, such as depressive symptoms, neuroticism, social networks, and number of chronic medical conditions. It also persisted in sensitivity analyses in which we sequentially excluded persons who developed Alzheimer's disease during each of the first 3 years of follow-up."
This, Dr. Barnes explains, was to address concerns that perhaps those in the cohort had undiagnosed or mild AD.
"Although our ability to infer causation may be limited, these kinds of additional controls strengthen our confidence in the findings," she noted.
Psychological Well-Being
Another recent study found that a sense of purpose in life was the most important factor in determining mental health outcomes after serious trauma (Am J Psychiatry. 2008;165:1566-1575).
"We found that the most important psychosocial factor associated with resilience or recovered status was a sense of higher purpose in life," Adriana Feder, MD, from the Mount Sinai School of Medicine, New York City, told Medscape Psychiatry when the study was first published online in November. "We also found that mastery, or having a strong sense of control over one's life, was significantly associated with recovered status."
This new study is reportedly the first to evaluate purpose in life and the risk for AD, but the investigators have evaluated other health outcomes in this same cohort and observed a reduced risk for death.
"Purpose in life is an indicator of human thriving that has been hypothesized to be related to better psychological well-being," Dr. Barnes said.
This study was funded by the National Institute on Aging, the Illinois Department of Public Health, and the Robert C Borwell Endowment Fund. The researchers have disclosed no relevant financial relationships.
Arch Gen Psychiatry. 2010;67:304-310.