✔ 最佳答案
回應問題, Placebo Effect中文是安慰劑效應, 是我們常聽到的所謂心理作用。
Definitions:
安慰劑效應(英文:placebo effect,源自拉丁文placebo解 - 我將安慰),又名 偽藥效應、假藥效應、代設劑效應等。
It's an apparent success of medication or treatment due to the patient's expectations or hopes rather than to the drug or treament itself
意指病人雖然獲得無效的治療,但卻「預料」或「相信」治療有效,而讓病患症狀得到舒緩的現象。
Causes:
許多人都認為是主覲(subjective) 大於客觀(objective) 因素。
A placebo effect occurs when a patient's symptoms are altered in some way (i.e., alleviated or exacerbated) by an otherwise inert treatment, due to the individual expecting or believing that it will work.
研究結果顯示安慰劑效應的形成是主觀因素。這有助解釋為何安慰劑效應在一些偏重主觀性質的病患(例如頭痛、胃痛、哮喘、敏感、壓力、痛症)中較容易表現出來。
Placebo Effect的原理: (how it works)
主要是base on幾個假設-Expectancy Effect&reflexes, Conditioning, Motivation & Modes of Endogenous Opiates.
受試者期望效應Subject-expectancy effect:
受試者期望效應引導病人有意識或無意識地報告病情得到改善,因此導致安慰劑效應的出現。Asbjørn Hróbjartsson 及Peter C. Götzsche 於文章中質疑「大部份病人有禮貌地傾向為迎合實驗人員而報告病情得到改善,即使他們並不感到改善。」主觀的偏見亦可能使病人潛意識相信病情因為得到關注及照料而改善。
條件反射/制約反應reflexes:
古典制約是一種關聯學習模式,使受訓者學習到特定情況下作出特定的反應。著名的例子是巴甫洛夫的狗實驗:於每次給予狗食物之前都發出鈴聲,經多次反覆後,每當鈴聲一響,狗就會自動分泌唾液,原因是狗已經學習到將鈴聲及食物關聯起來。所以,安慰劑使病人產生與有效藥物相似的生物反應,有可能是因為制約所造成
Motivation
Motivational explanations of the placebo effect have typically considered the placebo effect to be an outcome of one’s desire to feel better, reduce anxiety, or cooperate with an experimenter or health care professional (Price et al. 1999, Margo 1999). The motivational perspective is supported by recent research showing that nonconscious goals for cooperation can be satisfied by confirming expectations about a treatment (Geers et al. 2005).
Role of endogenous opiates(內生的興奮劑)
The discovery in 1975 of Endogenous opiates alias endorphins (substances like opiates but naturally prduced in the body) have changed matters in investing placebo effect. When patients who claimed to experience pain relief after receiving a placebo were injected with naloxone (a drug that blocks the effects of opiates), their pain returned, suggesting that the placebo effect may be partly due to psychological reaction causing release of natural opiates. (Sauro 2005)
Researches & Facts
Placebo Effect在醫學應用上使用安慰劑的準則引起了激烈討論。有執業人員認為使用安慰劑是可取的,因為安慰劑本身無害,有時候甚至可能有益。但Asbjørn Hróbjartsson 及Peter C. Götzsche 的研究公佈後,安慰劑有益這個觀點備受質疑。
Critics- 有人指對使用安慰劑的批評指出,對病人採用無效的療法是不道德的,告訴病人安慰劑是真正的藥物治療的做法是一種欺騙,長遠而言會危害醫生與病人的關係。批評又質疑使用安慰劑會延誤對嚴重病情正當的診斷及治療。
2000年的一個研究顯示,丹麥有48%的普通科執業員在過去一年曾至少開出10次安慰劑予病人。最經常使用的安慰劑治療是以抗生素醫治病毒感染及以維生素醫治疲勞。(專科及醫院醫生則較少使用安慰劑。)[16]於2004年,英國醫學期刊(British Medical Journal,BMJ)刊出的一份研究指出,有60%的以色列醫生使用安慰劑,通常的原因只是為了安撫病人或「迴避」病人要求使用不當藥物治療。在所有使用安慰劑的醫生當中,只有15%醫生告訴病人他們接受的是安慰劑或非特定藥物治療。
Modern clinical application(應用 & Its Significants效果):
Experimenters typically use placebos in the context of a clinical trial, in which a "test group" of patients receives the therapy being tested, and a "control group" receives the placebo. It can then be determined if results from the "test" group exceed those due to the placebo effect. If they do, the therapy or pill given to the "test group" is assumed to have had an effect.
有人認為這個Placebo Effect一個值得注意的人類生理反應,但亦有人認為這是醫學實驗設計所產生的錯覺。這個現象無論是否真的存在,科學家至今仍未能完全理解。
*另外, 一個實驗中的 placebo or a Placebo-controlled studie是指an inactive substance or fake treament used as a control in that experiment / given by a medical practitioner to a patient.
中英對照, 希望可以幫到你呢!!!!!!!!!!!!!!!!!!!
2007-03-07 18:06:10 補充:
這不是我在網上100% copy下來的, 而是根據我在psycho堂所學的而寫的,moreover, 為你做了少少research &剪裁(所以答案不會過份地長!!)如若需要更詳盡的information, 請參考:
http://en.wikipedia.org/wiki/Placebo
參考: 我的個人知識& my psychology professor & wikipedia!!!!