Sudarshan Kriya yoga is reversing many of the symptoms of depression, such as negative mood, disinterest, low energy, suicidal thoughts and feelings of guilt.
It's a significant discovery, say researchers at the University of Pennsylvania, as more than half the 41 million Americans taking antidepressants aren't being helped by the drugs.
The technique involves slow and calm breaths that are alternated by fast breaths, and which brings the person into a deep and calm meditative state.
It's easy to learn and practise, say the researchers who tested it on a group of 25 people who had been diagnosed with major depressive disorder (MDD), and who hadn't been helped by antidepressants. Half were taught Sudarshan Kriya yoga, which they practised regularly at home for two months, while the rest just carried on taking the antidepressants.
By the end of the trial, the yoga group showed 'significant' improvements and halved their HDRS (Hamilton Depression Rating Scale) score, a common measure of depressive symptoms. Those just taking the drugs saw no improvement in their score.
In addition to learning the breathing technique, the yoga group was also taught some yoga positions, meditation and stress-coping skills.