Science and curiosity: What is the placebo effect?

By Maria Chiara Rosace, Giuseppe Scarlata, Antonino Napoleone | October 7, 2021.

Imagine if you were to ask your doctor to get a drug migraine medicine prescribed to treat an annoying headache. The doctor accepts your request, you get a suitable pill and your condition improves. However, the pill contained no medicinal substance or active ingredient. How is it possible that your headache got better?

What is the placebo effect?

The term placebo comes from the future tense of the Latin verb placeo, literally meaning “I shall please”. In medical terms, it refers to treatments that have no real curative effect but work through suggestion. In fact, the placebo effect can be very strong and it is due to the release of therapeutic substances, such as endorphins or adrenaline, directly from the body of the patient who expects to receive a medicine.

The placebo effect is always there and it is usually very significant to the point of being often more powerful than the pharmacological effect itself¹.

Many unconventional therapeutic approaches or homoeopathic treatments are based on the placebo effect. Acupuncture, for example, may reduce pain, but it does not cure diseases².

How are placebos used in medicine?

Placebos are an essential component of evidence-based medicine. They are used to find out whether new drugs or therapies, surgical techniques, medical devices, diagnostic procedures, or other medical treatments have a real and safe effect on the health of people receiving treatments. During experimental studies called “randomized controlled trials”, half of the individuals receive active treatment, the other half a placebo. The placebo must look exactly like the drug under examination and have the same routes of administration, but of course, be devoid of the active ingredient. The subjects in the experiment do not know which treatment they are receiving (drug or placebo), and in this case, the clinical study is called “blind“.

There are also “double-blind” clinical studies in which neither the subjects nor the researchers know which treatment is being administered. The purpose of blind studies³ is to assess the placebo effect: if both groups show signs of improvement, then the treatment is not effective. Double-blind studies, on the other hand, serve to avoid potentially random results and ensure that the researchers are completely impartial in assessing the effects of the treatment and that there is no risk that the data may be biased or influenced by the psychological attitude of the investigators themselves. Thus in clinical trials, a new drug is only considered effective if it gives significantly different results from a placebo.

References

1. Erba M, 2016. Che cos’è l’effetto placebo? Disponibile online: https://www.focus.it/scienza/salute/che-cos-e-l-effetto-placebo
2. Parson P, 2009. 30-seconds theories. Ivy press limited
3. Studio in cieco | AISM | Associazione Italiana Sclerosi Multipla. Disponibile online: https://www.aism.it/studio_cieco