As TMFree readers would expect, meditation is not the save-all panacea for which it's marketed.
The majority of studies on Transcendental Meditation (TM) are NOT controlled studies, thus are weak. For example, TM studies do not compare TM with mindfulness meditation, prayer, buddhist chanting, nor with daily napping or exercise.
IF TM were compared with another contemplative practice, it would be impossible to know if the TM control group practices TM correctly because it's impossible to know what a person recites inside their mind. There is also no way to determine if a participant uses his or her correct mystical mantra, since the grid of reported TM mantras is not uniform. In another words, there is nothing scientific about the practice of trademarked Transcendental MeditationTM.
According to Dr. Herbert Benson, any word works as well as a TM mantra. Herbert Benson was co-researcher with Keith Wallace for the original TM studies in Scientific American. Benson then found identical results with other meditations and prayers that do not require secretive indoctrination. Benson called this The Relaxation Response.
Lo! mediterranean siestas provide some benefit!
As Gellman summarizes in the Wall Street Journal :
"Although uncontrolled studies have usually found a benefit of meditation, very few controlled studies have found a similar benefit for the effects of meditation programs on health-related behaviors affected by stress," the JAMA report said.
The report's findings show that meditation is perhaps less effective in alleviating stress-related symptoms than is widely believed, said Allan H. Goroll, professor of medicine at Harvard Medical School-Massachusetts General Hospital, in invited commentary also published Monday in JAMA Internal Medicine. "The studies overall failed to show much benefit from meditation with regard to relief of suffering or improvement in overall health, with the important exception that mindfulness meditation provided a small but possibly meaningful degree of relief from psychological distress," he wrote."