There have been a number of studies in the past 20 years which have attempted to scientifically examine whether intercessory prayer "works" - whether it can help people get better in a measurable way.
The most recent study is scheduled to appear in The American Heart Journal next week, but the results were released online yesterday.
Here is an excerpt from the NY Times coverage of the story this morning:
Prayers offered by strangers had no effect on the recovery of people who were undergoing heart surgery, a large and long-awaited study has found.
And patients who knew they were being prayed for had a higher rate of post-operative complications like abnormal heart rhythms, perhaps because of the expectations the prayers created, the researchers suggested.
Because it is the most scientifically rigorous investigation of whether prayer can heal illness, the study, begun almost a decade ago and involving more than 1,800 patients, has for years been the subject of speculation.
The question has been a contentious one among researchers. Proponents have argued that prayer is perhaps the most deeply human response to disease, and that it may relieve suffering by some mechanism that is not yet understood. Skeptics have contended that studying prayer is a waste of money and that it presupposes supernatural intervention, putting it by definition beyond the reach of science.
At least 10 studies of the effects of prayer have been carried out in the last six years, with mixed results. The new study was intended to overcome flaws in the earlier investigations.
The full NY Times article is here and it is a balanced report:Long-Awaited Medical Study Questions the Power of Prayer - New York Times It will only be available for free on the NYT website for the next week.
Here is the Washington Post coverage:Prayer Doesn't Aid Recovery, Study Finds The Post coverage I found a little bit flippant. But at least reading it will always be free!
Both articles mention that past studies were "flawed" - or at least the ones that showed a link between intercessory prayer and healing were flawed! No mention of why they were flawed.
Here's one of the best known studies showing a link:Positive Therapeutic Effects of Intercessory Prayer in a Coronary Care Unit Population Page 1 This study was published in the Southern Medical Journal in 1988. The research was done as a "double blind randomized protocol". In the early nineties this study was quoted by physicians - I first heard about it at that time, in a book on healing written by an M.D.
And here's a critique of the Southern Medical Journal study written by some obnoxious blogger - I found it yesterday - Skeptico: Prayer still useless -
My own opinion on this is the conventional Catholic one - prayer is efficacious, but don't ask me for a scientific analysis because no one (or at least I can't) can come up with one.