Patient expectations
Research has also looked at the expectations of the patient. Ross and Olson (1981)
examined the effects of patients’ expectations on recovery following a placebo. They
suggested that most patients experience spontaneous recovery following illness as most
illnesses go through periods of spontaneous change and that patients attribute these
changes to the treatment. Therefore, even if the treatment is a placebo, any change will
be understood in terms of the effectiveness of this treatment. This suggests that because
patients want to get better and expect to get better, any changes that they experience are
attributed to the drugs they have taken. However, Park and Covi (1965) gave sugar pills
to a group of neurotic patients and actually told the patients that the pills were sugar
pills and would therefore have no effect. The results showed that the patients still showed
some reduction in their neuroticism. It could be argued that in this case, even though the
patients did not expect the treatment to work, they still responded to the placebo. How-
ever, it could also be argued that these patients would still have some expectations that
they would get better otherwise they would not have bothered to take the pills. Jensen
and Karoly (1991) also argue that patient motivation plays an important role in placebo
effects, and differentiate between patient motivation (the desire to experience a symptom
change) and patient expectation (a belief that a symptom change would occur). In a
laboratory study, they examined the relative effects of patient motivation and patient
expectation of placebo-induced changes in symptom perception following a ‘sedative
pill’. The results suggested a role for patient expectation but also suggested that higher
motivation was related to a greater placebo effect.Reporting error
Reporting error has also been suggested as an explanation of placebo effects. In support
of previous theories that emphasize patient expectations, it has been argued that
patients expect to show improvement following medical intervention, want to please the
doctor and therefore show inaccurate reporting by suggesting that they are getting
better, even when their symptoms remain unchanged. (In fact the term ‘placebo’ is
derived from the Latin meaning ‘I will please’.) It has also been suggested that placebos
are a result of reporting error by the doctor. Doctors also wish to see an improvement
following their intervention, and may also show inaccurate measurement. The theory of
reporting error therefore explains placebo effects in terms of error, misrepresentation or
misattributions of symptom changes to placebo. However, there are problems with the
reporting error theory in that not all symptom changes reported by the patients or
reported by the doctor are positive. Several studies show that patients report negative
side effects to placebos, both in terms of subjective changes, such as drowsiness, nausea,
lack of concentration, and also objective changes such as sweating, vomiting and skin
rashes. All these factors would not be pleasing to the doctor and therefore do not
support the theory of reporting error as one of demand effects. In addition, there are
also objective changes to placebos in terms of heart rate and blood pressure, which
cannot be understood either in terms of the patient’s desire to please the doctor, or the
doctor’s desire to see a change.PLACEBOS AND THE INTERRELATIONSHIP BETWEEN BELIEFS, BEHAVIOUR AND HEALTH 313