Can positive thinking provide an improved outcome for an illness?

Question

Sometimes you hear that a gravely ill patient "just gave up" and subsequently died. Many people put great value in the healing power of positive thinking, with the more cynical ones blaming a bad progression of disease onto a "lack of will". Especially with cancer there are many people saying they survived it, because they fought the cancer.

Is there any evidence that the state of mind, the attitude of the patient has a real effect on the course of illnesses? I can imagine a positive attitude improving the quality of life, but I'm not so sure about having a real, physical effect on the illness.

Answer 1

Yes, both placebo and nocebo effects are real phenomena (although they are often exaggerated in popular media).

Google Scholar shows a lot of scientific papers on those, some of them provide a very detailed insight into those mechanisms:

The nocebo phenomenon, in which placebos produce adverse side effects, offers some insight into nonspecific side effect reporting. We performed a focused review of the literature, which identified several factors that appear to be associated with the nocebo phenomenon and/or reporting of nonspecific side effects while taking active medication: the patient's expectations of adverse effects at the outset of treatment; a process of conditioning in which the patient learns from prior experiences to associate medication-taking with somatic symptoms; certain psychological characteristics such as anxiety, depression, and the tendency to somatize; and situational and contextual factors.

—Nonspecific Medication Side Effects and the Nocebo Phenomenon, by Arthur J. Barsky, MD; Ralph Saintfort, MD; Malcolm P. Rogers, MD; Jonathan F. Borus, MD

The latest scientific evidence has demonstrated, however, that the placebo effect and the nocebo effect, the negative effects of placebo, stem from highly active processes in the brain that are mediated by psychological mechanisms such as expectation and conditioning.

—New Insights into the Placebo and Nocebo Responses, by Paul Enck, Fabrizio Benedetti, Manfred Schedlowski, Neuron - 31 July 2008 (Vol. 59, Issue 2, pp. 195-206)

Answer 2

To add to Krzysztof's answer. There were also studies suggesting that people can control somewhat the date of their death around major events.

This study, that won the 2001 Ig Novel for economics suggests that death rates changed around a change at the inheritance tax rate people.

This paper examines data from U.S. federal tax returns to shed light on whether the timing of death is responsive to its tax consequences. We investigate the temporal pattern of deaths around the time of changes in the estate tax system - periods when living longer, or dying sooner, could significantly affect estate tax liability. We find some evidence that there is a small death elasticity, although we cannot rule out that what we have uncovered is ex post doctoring of the reported date of death.

This study, that suggests the same with asian male Cancer patients around Chineese Harvest Moon Festival.

RESULTS: There were significantly fewer deaths overall in men before the holidays than after (p-value equals 0.0081), with most of the difference being due to cancer deaths, particularly among men over 75 years of age. For women, there were actually more deaths before than after the holidays. The data, stratified according to age, gender, disease and holiday, yielded only five out of 48 variables with a p-value of less than 0.05, which was slightly above chance, considering the large number of comparisons made. In four of the five situations, there were significantly fewer deaths before than after the holidays; but after Bonferroni correction, only the finding of fewer cancer deaths for men aged over 75 years before HMF was significant.

CONCLUSION: Other than cancer deaths in males, we found little evidence in this dataset of death postponement until after important holidays in the Hong Kong Chinese population.

While the studies are not conclusive, they do suggest that if a person really wants to live through some important occasion (like a major holiday) he or she may be able to postpone their death by a few days.