Mind and medicine: Placebo and nocebo

You can even mislabel a dummy pill as a brand-name drug, and some patients find that it works

November 18, 2017 03:01 pm | Updated 03:04 pm IST

  Control group:  The idea behind the comparative experiment is to check whether the treatment works, how safe it is and what side-effects it may have.

Control group: The idea behind the comparative experiment is to check whether the treatment works, how safe it is and what side-effects it may have.

When a clinical researcher or a pharmaceutical company wants to check whether a new medicine or treatment (a pill, injection etc) works, they choose a large-enough set of patients for the clinical trial. They are divided into two groups. One of them is given the actual treatment (pill or the injection). The other is chosen as the control group; this is given not the actual treatment, but a “dummy” pill or injection. Neither group knows who gets what, but believes that they get the right one. The idea behind this comparative experiment, which lasts for 4- 6 weeks, is to check whether the treatment works, how safe it is and what side-effects it may have — positive or negative.

The trials

Prior to the start of the trial, the researcher calls every participant and explains to him/her that this is being done to check the safety and efficacy of the trial and what possible side effects (positive and negative) could be faced, and asks each of them whether they consent to the trial. He also tells then that they are free to withdraw from the trial at any time and for whatever reason.

The reactions of the participants are of interest. Some of them say they already feel good. This is regardless of whether they were in the group that was given the drug or only offered the dummy. This phenomenon is termed the “placebo effect,” the name coming from the Latin phrase “placebo” meaning “I shall please.” The fact that they are being cared for already generates psychological benefit to them. This is not very different from how some people already feel better when they visit their friendly family doctor.

You can even mislabel a dummy pill as a brand-name drug, and some patients find that it works! A group led by Dr. Rami Burstein of Harvard Medical School labelled a placebo as the drug Maxalt (which is used to treat migraine headaches) and found it to be acceptable to many patients! While Maxalt treatment was clearly superior, the placebo effect increased in some participants. This indicates that labelling influences placebo.

Some patients are taken in by the price factor. They feel that the more expensive a drug is, the better it must be! A group led by Dr Dan Ariely of MIT recruited 82 people to test the efficiency of a painkiller drug. To one set they gave the drug priced at $2.50 per pill, and tested their ability to withstand the pain generated by an electric shock. To another set of 41 people, they gave the same drug sold at a attractive discount and tested their ability to withstand the same strength voltage-generated shock. The one who got the discount priced drug claimed they could bear far less pain then those who got the regular price drug. There appears to be the belief that a costlier product is better. Is this not what one sees even with cosmetics and several other consumer products? Many companies exploit this belief by wrapping their products in fancy packages and enticing the buyer — placebo in action.

Clinicians and researchers have also noticed the opposite of placebo occurring among some participants. Here the participant anticipates and feels adverse or negative reactions to a treatment. Dr. Walter Kennedy, who researched on this phenomenon coined the term “nocebo” in 1961, meaning “I shall harm you”, as the counterpart of placebo. Doctors mention that even telling the participants that a treatment might have some minor side effects — an itch or some pain — is sufficient for some to feel it.

A striking example of nocebo in action comes from a paper by Dr. Tinnermann and others in the October 6 issue of Science, with a commentary on it by Luana Colloca. They got the same skin cream packed in tow identical looking boxes — one marked at a higher price while the other was marked cheaper. They further warned that though the cream relieves itch, there might be a slight pain. The volunteer group that opted for the more expensive box said that they felt a little more pain than the group that opted for the less expensive box. The researchers, during the trial, also did imaging of the spinal region and the front part of the brains of the volunteers. The neural activity in the group that chose the costlier box was distinctly higher. The fact of the matter was — that the cream neither cured itch nor caused no pain at all! Colloca writes: “the anticipation of painful stimulation makes healthy study participants perceive non-painful and low-painful stimulations as painful and high-painful, respectively. Verbally induced nocebo effects are as strong as those induced through actual exposure to high pain”.

Shared decisionmaking

Professional medicine as a science is one side of the coin. The placebo–nocebo duality demands an understanding and allowing for the socio-psychological features of the patient, and this is the other side of the coin. The former is rigorous, meant for the body, and a “science.” The latter is individual-specific and, as some claim, is “art.” The care of the patient must thus involve what has come to be called as “shared decisionmaking” or SDM. It thus has an ethical dimension to it. A friendly, family doctor has been practising SDM. Hospitals, drug companies and insurance companies need to introduce SDM.

Given the numbers and the money involved, this is not easy, but not doing so has ethical implications. [For those interested, the paper by Brody, Colloca and Miller in J. Gen. Intern. Med . 2012 Jun; 27(6):739-42. doi: 10.1007/s11606-011-1977-1. Epub 2012 Jan 19 ].

dbala@lvpei.org

0 / 0
Sign in to unlock member-only benefits!
  • Access 10 free stories every month
  • Save stories to read later
  • Access to comment on every story
  • Sign-up/manage your newsletter subscriptions with a single click
  • Get notified by email for early access to discounts & offers on our products
Sign in

Comments

Comments have to be in English, and in full sentences. They cannot be abusive or personal. Please abide by our community guidelines for posting your comments.

We have migrated to a new commenting platform. If you are already a registered user of The Hindu and logged in, you may continue to engage with our articles. If you do not have an account please register and login to post comments. Users can access their older comments by logging into their accounts on Vuukle.