Therapy based on the controversial concept of 'mindfulness' works as well as some anti-depressant drugs, according to a major new study.
Inspired in part by Buddhist philosophy, mindfulness involves training the brain to deal with negative emotions using techniques such as meditation, breathing exercises and yoga.
Some critics have claimed mindfulness techniques can bring on panic attacks and lead to paranoia, delusions or depression.
But the new study - the largest-ever analysis of research on the subject - found mindfulness-based cognitive therapy (MBCT) helped people just as much as commonly prescribed anti-depressant drugs and that there was no evidence of any harmful effects.
People suffering from depression who received MBCT were 31 per cent less likely to suffer a relapse during the next 60 weeks, the researchers reported in a paper in the journal JAMA Psychiatry.
Professor Willem Kuyken, the lead author of the paper, said: "This new evidence for mindfulness-based cognitive therapy … is very heartening.
"While MBCT is not a panacea, it does clearly offer those with a substantial history of depression a new approach to learning skills to stay well in the long-term."
He stressed that different people required different treatments and mindfulness should be viewed as one option alongside drugs and other forms of therapy.
Professor Kuyken, an Oxford University clinical psychologist and director of the Oxford Mindfulness Centre, and other experts around the world have set themselves an ambitious target.
"We need to do more research, however, to get recovery rates closer to 100 per cent and to help prevent the first onset of depression, earlier in life," he said.
"These are programmes of work we are pursuing at the University of Oxford and with our collaborators around the world."
He stressed that while mindfulness may share a "lineage" with Buddhism and other "contemplative traditions", the way it was used in mindfulness-based cognitive therapy was "entirely secular".
"It makes complete sense to me that this wonderful faculty of thinking can both get us into trouble and also get us out of trouble," Professor Kuyken said.
"It's a sort of mental training. It's about training the mind so people can see negative thoughts, negative feelings, the early signs of a depressive relapse, and learn the skills to respond to those in a way that makes them more resilient."
A woman in one of his classes would start to have thoughts such as "I'm no good, I'm not a very good mother, I'm going to mess up my children and they are going to suffer from depression as I do", he said.
But, after the training, Professor Kuyken said the woman was "able to recognise her negative thoughts as negative thoughts not facts, and not engage with them as much".
"She developed a metaphor of a wrecking ball. Instead of being knocked over, she'd stand back and let the wrecking ball swing through her mind," he added.
Mindfulness has won the backing of NHS advisory body, the National Institute for Health and Care Excellence (Nice), and the Mental Health Foundation research charity. A study published in the Lancet last year also found mindfulness could be as effective as drugs.
However, the book The Buddha Pill: Can Meditation Change You? by psychologists Dr Miguel Farias and Dr Catherine Wikholm argued there was a need to look into the "dark side" of mindfulness.
"Mindfulness can have negative effects for some people, even if you're doing it for only 20 minutes a day," Dr Farias told the Guardian last year.
"It's difficult to tell how common [negative] experiences are, because mindfulness researchers have failed to measure them, and may even have discouraged participants from reporting them by attributing the blame to them."