In God:The Failed Hypothesis, Victor Stenger references a study that showed that prayer actually seemed to have a negative effect, perhaps due to performance anxiety.
There was at least one study that showed that prayer helps, but the Doctor who did it was a known fraud and all the other doctors who were credited on the study said they weren't actually a part of it and never consented to have their name put on it.
There was at least one study that showed that prayer helps, but the Doctor who did it was a known fraud and all the other doctors who were credited on the study said they weren't actually a part of it and never consented to have their name put on it.