Health Psychology : a Textbook

process may only occur if the individual believes that health professionals in white

coats can treat illness, that hospitals are where people get better and that medical

interventions should produce positive results. Patients’ beliefs may themselves be a

mechanism for explaining placebo effects. Perhaps the belief about a treatment has

either a direct effect on health through physiological changes, or an indirect effect via

behavioural change. For example, the belief that a treatment intervention will work, may

directly influence the individual’s immune system or alternatively may promote a change

in lifestyle.

Illness cognitions

For a placebo to have an effect, the individual needs to hold particular beliefs about their

illness. For example, if an illness is seen as long lasting without episodes of remission,

times of spontaneous recovery may not happen, which will therefore not be explained

in terms of the effectiveness of the treatment. Likewise, if an individual believes that

their illness has a medical cause then a placebo in the form of a pill would be effective.

However, if the individual believes that their illness is caused by their lifestyle, a pill

placebo may not be effective.

Health professionals’ health beliefs

Placebos may also be related to the beliefs of the health professionals. For example, a

doctor may need to believe in the intervention for it to have an effect. If the doctor

believes that an illness is the result of lifestyle, and can be cured by changes in that

Fig. 13-3 The interrelationship between beliefs, behaviour and health

PLACEBOS AND THE INTERRELATIONSHIP BETWEEN BELIEFS, BEHAVIOUR AND HEALTH 323