Great question and great responses. I believe that there have been studies which have found that pretty much any form of "laying on of hands" has a positive effect on the person who is suffering, whether physically or emotionally. And that this is why so many people find at least temporary relief after massage, PT, chiro, acupuncture, cranio-sacral, Reiki, Feldenkrais, etc etc etc..... as well as the various forms of emotional therapy.
The key word being temporary. I used to go to chiro and PT all the time, but dropped it all cold turkey, thanks to Dr. Sarno, and never looked back. The money I used to spend on that now goes to a personal trainer, who has pushed me beyond what I ever imagined myself doing.
I think the mind can be very powerful and faith in anything can heal if one believes enough.
My go-to books on this subject are
The Anatomy of Hope by Dr. Jerome Groopman, MD and of course the extraordinary
When The Body Says No by Dr. Gabor Mate, MD, which is #3 on my TMS booklist, after
The Divided Mind and
Hope and Help for Your Nerves.