Placebos are used to form a comparison point for new treatments, so the medication being tested can be deemed safe and effective.

Placebo clinical trials can be a single-blind (when the participants taking part don’t know whether they’re taking the actual drug being tested or the placebo), or a double-blind (when both the researchers and the participants aren’t aware whether they’ve taken the placebo or the medication being tested). A double-blind ensures that researchers treat the participants the same and don’t influence the trial in any way.

Placebos are considered an ‘unapproved’ therapeutic good, and a Clinical Trial Notification (CTN) or a Clinical Trial Approval (CTA) must be in place before they are used in an Australian clinical trial.

The Placebo Effect

The placebo effect is when patients start to feel better after taking the placebo because they believe that they will feel the effects of the actual medication (power of the mind). According to American Medical Researcher, Professor Ted Kaptchuk, "the placebo effect is more than positive thinking, or believing a treatment or procedure will work. It’s about creating a stronger connection between the brain and body and how they work together."

The ritual of taking medication and the ritual of treatment are big parts of the placebo effect. The feeling of getting attention and care can have an impact on how the body reacts to symptoms, while the act of taking medication can have a positive healing effect - even if the participant knows it’s not real medication.

Researchers consider the placebo effect before designing a clinical trial. The use of placebos allows doctors to see the positive effect the medication has on participants, not just because of the placebo effect, but because the treatment is actually treating the condition.

Why Are Placebos Effective?

There are some factors that influence how effective a placebo is:

Appearance of the placebo: If the placebo looks like a real tablet, the participant is more likely to believe that it’s real medicine.

Attitude of participant: If the participant is positive and expects the treatment to work, the higher the chance they’ll experience the placebo effect.

Brain chemicals: Placebos can trigger the release of the body’s natural pain relievers (endorphins).

Change in behaviour: The placebo might inspire the participant to take better care of themselves, and therefore help them notice an improvement in how they’re feeling.

Altered brain state (remembered wellness): The brain responds to an imagined scene and an actual visualised scene in the same way. A placebo might help the brain to remember a time before the onset of symptoms and cause a change in the body.

Control Groups

Participants are generally separated into two groups: an investigational group and a control group. The investigational group receives the new treatment being studied, while the control group generally doesn’t take any medication at all, or take a placebo instead. Participants in a control group are eventually given the treatment about 8-12 weeks into the study (usually during phase 3), after information has been collected on how they do without the new treatment.

Placebos would never be used in a clinical trial if it would put participants at risk, which is why placebos are rarely used in cancer clinical trials.

Open-Label Placebos

An open-label placebo is when participants are aware that they will be taking placebos. People who are aware that they’re taking placebos can still feel the ‘placebo effect’ as they feel helpful that they are taking place in a clinical trial and have expectations of relief. The very act of taking medication (opening the bottle, and swallowing a tablet) also has a large impact on participants and the ‘placebo effect.’

Ethical & Negative Issues

The use of placebos is an ongoing debate within the medical community. Some people view placebos as being unethical when effective treatments already exist (participants are denied treatment), or say that alternative study designs could cause less harm. Other people argue that placebos are crucial to protect the public from ineffective or dangerous medication.

When it comes to vulnerable groups (children, people with a mental illness and terminally sick people), the use of placebos is hotly debated. Placebos are usually limited amongst children, as they can’t give their consent.

When an effective treatment already exists, it is unethical to create a placebo group where patients will be denied the proper treatment.

The Nocebo effect is a negative reaction to the placebo which may include nausea and skin rashes. It may be triggered by a participant being told what side effects they might expect before taking part in the clinical trial.

Although the use of placebos will always be a controversial topic, it is clear that they serve an important purpose in clinical trials and play a big part in determining what medications and treatments are most effective and safe for the public to use.