Placebo in the spotlight of research

What is a placebo?

A placebo is a drug that has no active ingredient, although it can have a healing effect. The placebo is of Latin origin (i.e. placebo="it will please me") and usually contains only fillers such as lactose and starch. The effect produced is known as the placebo effect. How this effect is caused is not yet clear. However, it is assumed that the so-called self-healing powers of the human body and the resulting belief in the drug are the origin of the effect. Therefore, the patient's expectations may determine the effectiveness of the treatment. As a positive effect: The patient believes in the drug and hopes for a healing process - and this occurs accordingly. As a negative effect: Because of the conviction that the drug does not help, it may possibly also fail or even harm (i.e. nocebo effect).

Areas of use of placebo agents:

As mentioned earlier, placebos are used in some studies to compare and investigate the effects of (new) drugs. In such cases, the active substance is administered to the study group, while the control group receives the placebo drug. This is similar in appearance, colour and taste (e.g. placebo tablet or placebo capsule) to the real drug. Only after the drug to be tested can show a significantly better effect than the placebo is it classified as effective.

Placebos can also be used in practical therapy. For psychological, mild or non-life-threatening causes, a treating physician may find it useful to consider placebo therapy. On the other hand, a helpful medication may not be applicable for medical reasons, which is why the placebo is administered as an alternative.

Mode of administration of placebo:

The way placebos are administered can also alter the placebo effect. A study published in 2015 evaluated data from 149 randomized trials that examined the treatment of knee pain. In this study, placebos injected into the joint were able to show the greatest placebo effect. Placebo creams applied to the joint site followed in second place, and placebo medications in tablet form recorded significantly less effect than the first two.

Expensive placebos more effective?

Another double-blind, randomized, crossover study, published in 2015, examined the relationship between drug price and their effect. In This Placebo Study, 12 Parkinson's patients were given harmless saline solutions. One group received what appeared to be a "cheap" drug, while the other study group received an "expensive" drug at 100 times the price. According to the results, patients who were given the "more expensive" drugs were found to have an average 28% increase in motor skills over those given "cheaper" placebo drugs.

Placebo and brand name:

Brand name can also be a factor, according to a 2002 study published in the scientific journal Ann. Intern. Med., published in 2002, the brand name can also influence the effect of a drug. In this study, 835 women with headaches were divided into four groups. Each group received real aspirin (active ingredient: acetylsalicylic acid or ASA for short) or a placebo as follows:

• Group 1: real aspirin from the best-known manufacturer.
• Group 2: same aspirin, but brand name removed
• Group 3: placebo with the same brand name
• Group 4: placebo without brand name

While the first two groups consecutively gave the best results, 64% of the subjects in group 3 noted an improvement. In group 4, it was only 45% of the subjects.

Conclusion:

Still a placebo-controlled study is considered a good standard of an investigation. Placebos are also used in practical forms of therapy when circumstances permit. Nevertheless, the realization that not all placebos have the same effect and could even achieve clinically relevant effects should not be underestimated. Especially since when designing the methods of clinical trials, which are placebo-controlled, close attention should be paid to ensure that the placebo also meets the optical parameters and, if possible, does not falsify the comparative results.

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