"With regard to transcendental meditation’s claim of “508 scientific studies”, only 24 (3%) of these were randomised controlled trials and of these, at least 6 were published by lead-authors employed by transcendental meditation- (TM)-linked institutions, primarily the Maharishi University of Management. Such links naturally raise questions about conflicts of interest and objectivity in the reporting of results, particularly in the light of the strongly commercialised nature of the TM technique.
Of the 24 studies of TM, 22 were clinical trials and 2 were physiological trials assessing effects after brief training giving 37 comparisons. The author was the trainer in one study, while in 5 studies the author was employed by an institution that had formal affiliations with the TM organisation. TM was compared to low credibility controls in 19 comparisons, to moderate credibility controls in 4 instances and to high credibility controls in 14 instances. Sample size ranged from 20 to 250 participants, sample size per treatment arm ranged from 10 to 78. Drop-out rates varied from 0% to 55%. In 13 studies the statistical methods were inappropriate or not clearly described and in 16 studies the author’s conclusions were not supported by the analysis and results. "