Why Can Ineffective Treatments Appear to Be Effective?

So-called medical (traditional and alternative) treatments are perhaps most often debated to a standstill with this sentence:

I know it works because I tried it myself!

Advocates of alternative treatments (phytotherapy, homeopathy, detoxes, high-dose vitamins, etc.) use this argument most frequently. Challenging it or presenting scientific evidence often provokes an emotional response, because the other person thinks you are implying that they are being deceptive, that what they say is irrational, or both. I therefore think it is important to keep addressing this issue. So let me explain once again why ineffective treatments can “appear” to be effective.

To make this less tedious, let us consider a concrete situation to which no one, or almost no one, would object emotionally. Consider a patient whose diagnosis remains uncertain but who suffers from recurrent pain and says they have benefited from homeopathy (a form of alternative treatment for which there is genuinely not the slightest scientific evidence).

Why, then, does the patient experience less pain after consulting the homeopath?

There are countless reasons, and below we will look at some that are well described in psychology:

1. The patient may think their pain occurs less often without any actual change; remember bias.
2. The healer may have convinced the patient that their pain before treatment was worse than it really was; remember bias.
3. The patient may report improvement in line with what they believe the healer hopes for and expects; social desirability.
4. The patient tends to remember improvements / positive experiences preferentially over deterioration; remember bias.
5. Patients may interpret ambiguous changes in symptoms as signs of improvement.
6. Many symptoms disappear or improve on their own; the natural course of the disease.
7. Many symptoms fluctuate; the natural course of the disease.
8. Extremes detected in repeated measurements become less extreme; the phenomenon of “regression toward the mean”.
9. Patients use several treatments at once and then wrongly attribute an improvement to a particular treatment.
10. Patients expect to improve; the placebo effect.
11. Patients are conditioned to improve; the placebo effect.
12. Improvement from enthusiasm about receiving a new intervention; the novelty effect.
13. Improvement from enthusiasm about receiving an exotic therapy.
14. Improvement through compassionate care and the attention received.
15. Improvement because of the time spent with the healer.
16. Improvement through the effort and resources invested by the patient.

All these phenomena, and certainly a few more, operate together and can produce a clinical outcome that makes ineffective, or even somewhat harmful, treatments look effective. In any individual case, it is impossible to decide precisely what brought about the improvement. The only way to be sure that the treatment’s specific effects, homeopathy in this example, are involved is to conduct one, or preferably several, controlled clinical trials.

- Related topic: How Can Our Critiques of Traditional and Alternative Medicine Improve Health Care?