Research in the area of therapy, stress reduction, and cancer has led to mixed findings. This can confuse reporters and patients alike. For example, a research study done in 1989 by David Spiegel and colleagues seemed to link a difference in survival with taking part in a support group. But other researchers who did the same kinds of studies did not have the same outcomes.
A 2004 study review pooled the results of many well-designed studies of cancer patients getting psychotherapy. With more than 1,000 patients in the final results, no effect was found on survival.
In 2007, other researchers looked at all the previous studies. They found that no randomized clinical trial set up to look at survival and psychotherapy has shown a positive effect, except in cases where medical care was a confounding factor. (This means that one group’s medical care could have been different enough to affect the results.)
Finally, Spiegel himself tried to repeat the 1989 study with a new group in 2007 to see if the result would be the same as that of their earlier trial. The 2007 study reported better quality of life among those who took part in the group, but this time there was no difference in survival.
How positive thinking affects patients with serious illnesses
Life Change 