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Clinical Trials & Implications of Placebo


Clinical Trials & Implications of Placebo

Randomized controlled trial (RCT) established that placebo effect is for real and that the health of people, who belonged to the ‘placebo- control’ group, sometimes did dramatically improve.

There is only a limited understanding regarding the exact mechanisms behind the working of the placebo and its effects as the experiments with placebo has mainly been confined to randomized clinical trials (RCTs) with healthy subjects.

Some Interesting Case Studies and Different Placebo Effects

An RCT in 262 patients who suffered from irritable bowel syndrome was carried out. Here they investigated whether placebo effects can be separated into two main components:

a) Placebo ritual alone, consisting of a placebo acupuncture device (group A)

b) Placebo ritual in addition to supportive patient—clinician relationship consisting of attention, warmth, confidence and thoughtful silence - and if these two components can be combined effectively for positive clinical outcome(group B)

c) This was then compared to the no treatment group (group C)

After 3-weeks, a significant relief was reported by the subjects as follows:

a) 62% of participants in the placebo ritual plus supportive care group Group B

b) 44% in the placebo ritual alone group Group A

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c) 28% in the no-treatment group C

Follow ups showed same effect. These studies showed that placebo effects can achieve clinical significance with time and that these effects can be incrementally added.

Another analysis showed that patient agreeableness, and openness to experience played a great role in determining the way in which people responded in the group B. The clinician’s approach too played a significant role.

Placebo delivery -It was studied whether different methods of placebo delivery produced different placebo effects. In a large study comprising of 270 patients who experienced chronic arm pain it was discovered that a sham device such as acupuncture had more impact than an oral inert pill.

Depending on the complaint of the patient and the time for which the pill was delivered different placebos had different effects.

Similarly open treatment was more effective than hidden treatment with placebos

Clinicians' expectations also seem to have a say in placebo responses

Loss of placebo mechanisms has important clinical significance as observed in patients with Alzheimer’s disease. The role of cognition in enhancing placebo effect  and thereby responding to treatment has been unearthed.

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Studies have revealed that the overall outcome of a treatment depends on a combination of pharmaco- physiological action of the treatment administered and also the psychosocial context in which it is delivered.

Common symptoms that can have significant response to placebo include – headaches, depression, urinary and symptoms of sexual dysfunction.

Diseases that frequently show placebo response include – Parkinson’s Disease, Alzheimer’s disease and Schizophrenia.

Research has also provided evidence of the existence of placebo effects even when no placebo was administered. Placebos have the ability to activate biochemical pathways similar to the required drug.

Placebos can help to reduce the overall drug intake.

All these are reasons enough to call for a better understanding of  the placebo effect and to augment their use in clinical practice.

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