In an effort to help students understand both the power and limitations of the placebo effect, I came up with the following hypothetical experiments (that I would love to actually conduct) and predicted results.  Obviously many details are omitted  for simplicity and brevity, but hopefully they are an interesting illustration of what might be happening.  The experiments are followed by three questions that I pose to my students. The last question, while somewhat rhetorical, is meant to help understand the success of many if not most alternative therapies.   Feel free to leave your comments.

Experiment 1: Lower Back Pain

1. Advertise for people with chronic lower back pain.
2. Each subject is randomly assigned a number from 1 to 4.
3. Each subject then goes to the corresponding numbered room and will be contacted one week later for follow-up.

Room 1:  The subjects are told that nothing will be done and that they should leave.  (ie: “The experiment was cancelled.”)

Room 2:  The subjects are sat down and told to focus on their breath, visualize the pain and let it go.

Room 3:  The subjects are told everything that they were told in room 2 and that they are getting pain medication, but they are given a sugar pill and told to take one a day.

Room 4:  The subjects are told everything that they were told in room 2 and that they are getting pain medication and they are given scientifically proven pain medication and told to take one a day.

After one week the graph shows the percentage of subjects claiming that their back pain has significantly decreased.

Experiment 2: Bacterial Infection

1. Advertise for people with a specific bacterial infection as shown by blood work.
2. Each subject is randomly assigned a number from 1 to 4.
3. Each subject then goes to the corresponding numbered room and will be contacted one week later for subsequent blood test.

Room 1:  The subjects are told that nothing will be done and that they should leave. (ie: “The experiment was cancelled.”)

Room 2:  The subjects are sat down and told to focus on their breath, visualize the infection and let it go.

Room 3:  The subjects are told everything that they were told in room 2 and that they are getting an antibiotic, but they are given a sugar pill and told to take one each day.

Room 4:  The subjects are told everything that they were told in room 2 and that they are getting an antibiotic and they are given a scientifically proven effective antibiotic and told to take one a day.

After one week the graph shows the percentage of subjects with blood tests that show decreased bacterial infection.

Questions

1.  Are the positive outcomes from Room 1 in both experiments a result of a placebo effect?

2.  What is the most significant difference between the two experiments?

3.  If you were one of the few subjects from Room 2 in Experiment 2 that had a positive outcome, wouldn’t it be tempting to think that you were able to clear up a bacterial infection simply by focusing and relaxing?  Wouldn’t you want everyone to know?