IELTS Online Practice Materials

Placebo

(A) A placebo is a form of treatment used in medicine which is intended to have no actual effect on the condition being treated of its own. Sometimes patients given a placebo treatment will have a perceived or actual improvement in a medical condition, a phenomenon commonly called the placebo effect or placebo response.

(B) Placebos are an important methodological tool in medical research. Common placebos include inert tablets (like sugar pills), fake surgery, and other procedures based on false information. However, in a 2010 study, patients who knew they were receiving a placebo pill showed better improvement in condition than those who did not know the pills were placebo. It has also been shown that use of therapies which patients are unaware of is less effective than using ones that patients are informed about.

(C) Brain imaging techniques done by Emeran Mayer, Johanna Jarco and Matt Lieberman showed that placebos can have real, measurable effects on physiological changes in the brain. Placebos can produce some objective physiological changes, such as changes in heart rate, blood pressure, and chemical activity in the brain, in cases involving pain, depression, anxiety, fatigue, and some symptoms of Parkinson’s. In other cases, like asthma, the effect is purely subjective, when the patient reports improvement despite no objective change in the underlying condition.

(D) The placebo effect is a pervasive phenomenon; in fact, it is part of the response to any active medical intervention. The placebo effect points to the importance of the patient’s perception and the brain's role in physical health.

(E) A placebo has been defined in a 1983 paper by McDonald, Mazzuca, and McCabe as "a substance or procedure ... that is objectively without specific activity for the condition being treated". Under this definition, a wide variety of things can be placebos and exhibit a placebo effect. However, the placebo effect may be a component of legitimate pharmacological therapies: pain-killing and anxiety-reducing drugs that are given to a patient secretly are less effective than when the patient knows they are receiving them. Likewise, the effects of stimulation from implanted electrodes in the brains of those with advanced Parkinson's disease are greater when they are aware they are receiving this stimulation.

(F) Although the placebo effect is typically associated with deception in order invoke positive expectations, studies carried out by Harvard Medical School have suggested that placebos can work even without deception. In an attempt to implement placebos honestly, eighty patients were divided into two groups, one of which received no treatment, while the other group were provided with placebo pills. Although it was made clear that the pills had no active ingredient, patients still reported adequate symptom relief. Another similar study, in which patients suffering from migraines were given pills clearly labelled placebo, still reported improvements of their symptoms.

(G) Another negative consequence is that placebos can cause side-effects associated with real treatment. One example of this is with patients who have already taken an opiate, who can then show respiratory depression when they are given a placebo that mimics the opiate they had taken before.

(H) Withdrawal symptoms can also occur after placebo treatment. This was found, for example, after the discontinuation of the Women's Health Initiative study on hormone replacement therapy for menopause. Women had been on placebos for an average of 5.7 years. Moderate or severe withdrawal symptoms were reported by 4.8% of those on placebo compared to 21.3% of those on hormone replacement.

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Adapted from Wikipedia