Jeff Langmaid reviews fourteen studies on pain relief. Every single one reported reduced pain scores, though not all reached statistical significance. He argues it would be too much of a coincidence if the observed brain changes weren't responsible for the relief.
There were 14 studies that assessed some form of pain, like pain intensity or unpleasantness. Every study measuring pain after the intervention showed a reduction in pain scores. I'll repeat that. Every study measuring pain showed a reduction in pain scores. So not every score reduction was statistically significant, but all of them lowered it. So none of the studies directly established that observed brain changes caused the reduction, but that would be a heck of a coincidence if it didn't have an impact on it, as you can imagine.
