Prayer may be the most universally applied form of treatment for sickness, injury and disease. It's used around the world, across cultures and for at least as long as reports of human suffering reach back. But nobody seems to know whether it really works.
A surprising number of researchers, some representing mainstream institutions and applying standard research protocols, have taken up this controversial and provocative question in recent years.
Studies that have found associations between religious activities or beliefs and good health fail to prove cause and effect. And studies targeting the act of prayer are harder to do and have so far been inconclusive.
While some research has demonstrated health benefits from praying for oneself and--perhaps more arrestingly--being prayed for by others (which is known as intercessory prayer), most of these studies have problems that leave experts questioning their validity. Many use too few participants to produce statistically accurate results or apply imprecise measures to such variables as pain and recovery.
And most important, events that believers would consider manifestations of God can be maddeningly difficult to account for in a way that satisfies science.
"Trying to scientifically determine prayer's effect on health is nearly impossible," says Adriane Fugh-Berman, assistant clinical professor of health-care science at George Washington University School of Medicine in Washington, D.C., and author of the book "Alternative Medicine: What Works" (Lippincott Williams & Wilkins). "Prayer studies are interesting, but from a public health point of view, they are not the best place to put our dollars."
Researchers who head many of the studies acknowledge the topic's inherent challenges, but believe its importance outweighs its problems.
"Can prayer heal? Probably not. And [it's] difficult to prove," says David Larson, president of the National Institute for Healthcare Research, a think tank in Rockville, Md., that focuses on spirituality and health. "Is prayer associated with [relieving] illness? Yes. And that's why we're interested in prayer studies."
In a highly publicized study, researchers at the Duke Clinical Research Institute in Durham, N.C., found that prayers had a positive effect on health outcomes--even prayers from strangers, even when patients did not know they were being prayed for.
