That seems to be one of the exact concerns of the experts cited in the article: "Many of the studies on mindfulness and meditation, the authors wrote, are poor

That seems to be one of the exact concerns of the experts cited in the article: "Many of the studies on mindfulness and meditation, the authors wrote, are poorly designed—compromised by inconsistent definitions of what mindfulness actually is, and often void of a control group to rule out the placebo effect."