It is not only emotions that have a corresponding biological effect; other cognitions are important too. Thoughts and, in particular, beliefs can have a physical effect on the body. This has been studied extensively observing the placebo effect. The placebo effect, in which an inert substance has a measurable effect on the physical body, is not only a good example of how the mind and body interact, but also allows us to examine specific beliefs.
Examination of the placebo effect reveals that biological changes occur in the body that mimic the actions of the actual medication, and actual biological changes thus occur based on beliefs. 7 The placebo effect is particularly strong in relation to pain relief, as pain signals are intrinsically linked to areas of the brain that also respond to emotions.
This is discussed in detail in chapter 17. The nocebo effect, on the other hand, occurs when a patient who believes that a treatment will cause harm experiences an adverse effect. 8 This is particularly relevant to rehabilitation. It is important for athletes to hold positive beliefs regarding their treatment and the outcome.
The nocebo effect seems to stem from the hippocampus, and as a consequence, memory is important. 9 So too, therefore, is an athlete’s prior experience of injury treatment. If an athlete is identified as having negative beliefs regarding recovery or treatment, psychological intervention is especially warranted. Examining how the placebo and nocebo effects occur highlights the psychological traits that are relevant. Placebo effects depend on the functioning and efficiency of the reward system, and individuals’ responses to placebos differ.
Expectation, conditioning and beliefs are important. Branded pills work better than generic. Because of previous experience affecting expectations, placebo prescribed four-times-a-day is more potent than twice-a-day, and injections are more effective than tablets. 7 The stronger the expectation, the stronger the effect. Athletes base their beliefs on prior experience and from interaction with the rehabilitation team.