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Yoga for depression? Unimpressive science from impressive institutions
The title of the press-release was impressive: 'Columbia and Harvard Researchers Find Yoga and Controlled Breathing Reduce Depressive Symptoms'. It certainly awoke my interest and I looked up the original article. Sadly, it also awoke the interest of many journalists, and the study was reported widely - and, as we shall see, mostly wrongly. According to its authors, the aims of this study were "to assess the effects of an intervention of Iyengar yoga and coherent breathing at five breaths per minute on depressive symptoms and to determine optimal intervention yoga dosing for future studies in individuals with major depressive disorder (MDD)". Thirty two subjects were randomized to either the high-dose group (HDG) or low-dose group (LDG) for a 12-week intervention of three or two intervention classes per week, respectively. Eligible subjects were 18–64 years old with MDD, had baseline Beck Depression Inventory-II (BDI-II) scores ≥14, and were either on no antidepressant medications or