Georg Ivanovas From Autism to Humanism - systems theory in medicine
2.4 The placebo effect
In the last years there is a gradual shift in the understanding of placebos. Some authors investigate how the expectation of a patient influences the outcome of a therapy. Although this is only one aspect of placebos, it is a change of perspective. The centre of investigation is no longer the effective remedy but the reacting person.
Benedetti et al. administrated drugs and stopped administration openly and hidden by an automat. So some patients knew when they were treated and some not. The results show that the knowledge of the administration influences the outcome. In anxiety the knowledge was the only therapeutic factor. But the effect was also strong in postoperative pain and in Parkinson’s disease (Benedetti et al 2003). The authors are cautious to call this a ‘placebo effect’, as there cannot be such an effect without a placebo. They talk of “meaning and meaning-induced expectations”. This is supported by other authors: “We define the meaning response as the physiologic or psychological effects of meaning in the origins or treatment of illness; meaning responses elicited after the use of inert or sham treatment can be called the "placebo effect" when they are desirable and the "nocebo effect" when they are undesirable” (Moerman/Jonas 2002).
This shift in the understanding of placebos is a step forward, as it comprises a notion of information which is no longer congruent with the notion of signal (chap. 4.1) and it refers to the semiotic aspects (chap. 3.9) of therapy all issues exceeding current concepts of the placebo effect, but necessary to understand the healing process. Nevertheless, Benedetti’s work does not refer to placebos but only to one subject (expectation). It can be assumed that the reaction (and the expectation) of a young male after an operation will be different when helped by a young beautiful female nurse or by an old male nurse. This was, at least, my personal, invalid experience when working in traumatology. Validated is, however, that it makes a difference in pain reaction, if the partner of the test person is present in a room (Flor 2002). That is, expectation is nothing static but changes according to the environment.
In order to come to reliable and reproducible results about the placebo effect it would be necessary to eliminate all social factors which might interfere with the defined process. But also this would be no solution. In hamsters it has been shown that wounds heal quicker if the wounded is in a normal social context. If the animals were in a tube the wound even became worse (Detillion et al 2004). That is, a wound healing substance might be effective in the first context, but would prove to be a placebo in the second.
Patients in hospitals find themselves often in comparable situations as the hamsters in the glass tube (McCarthy 2004), even more so when a trial is undertaken, where every disturbing factor is excluded. Thus, as it is impossible not to communicate (chap. 3.7), it is impossible to exclude the placebo effect by restricting communication. Furthermore, excluding and controlling everything is bad medicine. It leaves the patient in a miserable state. The results of effectiveness found under these conditions have no significance for conditions where humans are treated in a meaningful social frame.
But expectation is even more complex. A rat which had been fed saccharine-flavoured drinking water that was temporally paired with a powerful immunosuppressive drug, cyclophosphamide, exhibited persistent immunsuppression despite discontinuation of the drug (Ader/Cohen 1975). This means that classical conditioning contributes to the placebo effect, such that previous medication, experience and general habitude alter the outcome of a therapy. The whole socialisation taints expectation.
In Germany 60% of stomach ulcers can be healed with placebos but practically none in Brasilia. But it is nearly impossible to treat German hypertension with placebo, whereas Brazilians react quite well. On the European continent a suppository is much more effective, in England the oral administration is superior (Klein 2003).
A biopsychosocial model for the placebo effect (Roth 2003).has to take into account that every therapy is embedded in a process of signification which influences the outcome and, recursively influences the signification. The results are often as unexpected as contradictory. For example, in Parkinsonian patients there was a verbally induced expectation of increase/decrease of growth hormone and cortisol. This did not have any effect on the secretion of these hormones. However, if a preconditioning was performed with sumatriptan (which stimulates growth hormone and inhibits cortisol secretion), a significant increase of GH and decrease of cortisol plasma concentrations were found after placebo administration. This happened although verbally opposite suggestions were given. (Benedetti et al 2002). That is, the placebo effect was adverse to the expectations but in line with experience or ‘body memory’.