Friday, 4 January 2008

Placebos and body shape

My friend John Baez pointed me to an interesting news story. This reports research on the effects of explaining to hotel maids that they do more exercise than the recommended daily amount. The odd thing is that many such workers' bodies don't reflect this physical activity, and at the same time they report themselves as doing little exercise. When one randomly selected group had the truth explained to them, there was a decrease in their weight and waist-to-hip ratio - and a 10 percent drop in blood pressure.

Naturally, one might think that this information must have altered other aspects of the maids' lives. Perhaps they were now behaving in a healthier way. An expert is wheeled in to suggest this must be so as the placebo effect only alters subjective aspects of health.

With all the evidence available (some touched on here, here, and here), could it be that the belief that placebos only effect one subjectively is a defense against the troubling thought that language can have an effect on our body?


DrBob said...

What a fascinating study David. Thank you for posting about it.
I think the belief that placebo can only affect subjective experience is indeed an ignorant belief. You'd think an intelligent scientist would understand that we are meaning seeking creatures and that what sense we make of our lives influences the physical reality of our bodies.
I reckon the blindness comes from a kind of materialistic fundamentalism.
It's this same extreme dualism that leads to the thinking that placebo is some kind of trick or pretence. It's not.

david said...

It's odd how placebo is treated as an irritating intrusion, which must be subtracted to uncover the efficacy of the 'real' medication.

On the most generous interpretation, I could understand reluctance to want to consider one's efficacy as involving placebo, as bringing into question a lack of honesty in the doctor-patient relationship. Can an ideal relationship involve deception?

As I was suggesting here, however, we could imagine a path to such a relationship which allowed it.

DrBob said...

I think you hit the nail on the head here David with this concept that the placebo effect is something to be "subtracted".
I think the reality is that the so-called "placebo" effect is an integral part of EVERY therapeutic intervention. It can't be subtracted, and, even more than this, there is no way to prove in any individual case whether the outcomes of the intervention were due the pharmacological actions, say, or the "non-specific" ones.
The honest approach is to admit that.
The deliberate use of a dummy medicine which the therapist believes to be inactive but tells the patient it's not.....well, that IS dishonest in my opinion, and is a breach of the trust on which a therapeutic relationship is built.

david said...

I completely agree with you about placebo as an integral part of treatment.

I think I can envisage a situation where one might knowingly give what one believes to be an inactive pill without at the time admitting this. For example in the case I quoted:

"I was recently consulted about a patient who had a long-standing and refactory clinical depression. She had tried most of the available antidepressants but had not really had any good relief for her depression until she had been enrolled in a trial of a new drug. Her improvement since starting the new treatment had been dramatic and sustained, much to the relief of her clinical caregivers. She had, however, been in a placebo group in the trial. I was asked what her treating clinicians should tell her."

Perhaps you see no other way out of the depression for the patient. After her improvement it may then be possible to develop the proper kind of relationship where such deception would be unwarranted.