I heard back from Dylan Evans who tells me that the placebo effect on actual medication has not been properly studied to date: "It's a good question, and one that hasn't really been tested. There some relevant evidence, though. For example, people who take headache pills with a well-known brand stamped on them get more relief than those who take the same pills but without any identifying brand name on them. See:
Branthwaite, A. and P. Cooper (1981). "Analgesic effects of branding in treatment of headaches." British Medical Journal 282: 1576-1578."
He tells me that the fourth chapter of his upcoming book "Placebo: The Belief Effect" discusses the concept.
F U R T H E R R E S E A R C H
In the paper "DO BRANDS BENEFIT CONSUMERS?" by Tim Ambler "Branthwaite and Cooper (1981) showed that branding not merely matches product to consumer need, but, in the case of analgesics, actually increases functionality. No doubt this is true for other categories where the functionality lies in the user’s mind, entertainment for example. The Disney experience and the Disney brand are hard to distinguish. Brands were significantly more efficacious in relieving headaches, irrespective of whether the tablets contained analgesics or placebos."
PLACEBOS: CURRENT STATUS by VANDANA ROY and TUSHAR ROY Abstract: "The efficacy of a drug, in addition to the actual pharmacological effect, depends on a number of nonspecific factors, commonly termed as the placebo effect. These non specific factors include the physician’s attitude, patient’s personality, the doctor patient interaction, the appearance of medication, nature of the therapeutic or diagnostic procedure and the environment. The placebo effect may yield beneficial clinical results in 70% of diseases that range in severity from common cold to angina pectoris. The placebo effect may not distinctively differ from a true pharmacological effect of a drug and may even be associated with adverse effects known as the nocebo effect.
In medical therapeutics, physicians have relied on nonspecific factors that evoke the placebo effect. Placebos are also used in clinical trials to distinguish the pharmacological from the nonspecific effects. The use of placebos in clinical trials has raised ethical issues, discouraging their use in studies where effective, alternative treatments are available.
It is in the patient’s benefit that the placebo effect be maximized, in the form of a healthy doctor patient relationship. It is imperative for investigators to understand the extent to which placebo effects can account for improvements observed in clinical studies. This review describes some aspects of the role of placebos in patient management and drug research."
© Robert Karl Stonjek 2002