A team of psychologists is appealing for volunteers to take part in a study using ancient and modern techniques to prevent suicidal depression.
There are 5,000 suicides per year in the UK
The University of Oxford researchers hope to discover whether modern therapy and ancient meditation can halt sadness or stress spiralling into depression.
The method is already used to treat Chronic Fatigue Syndrome in Oxford.
Volunteers will undergo psychological testing before and after a nine-week course, as part of the major trial.
Professor Mark Williams and Dr Melanie Fennell are co-ordinating the large scale pilot involving classes for people who have been depressed and suicidal in the past but have now recovered.
Dr Williams said: "We have found that, during a period of crisis in which someone becomes depressed and suicidal, an association is learned between the various symptoms (low mood, physical pain, suicidal tendencies, and so on).
"This means that when the negative mood happens again, for any reason, it will tend to trigger all the other symptoms. This is called Cognitive Reactivity.
"The discovery that, even when people feel well, the link between negative moods and negative thoughts remains ready to be reactivated, is of enormous importance.
"It means that preventing future crises depends on learning how to keep mild upsets from spiralling out of control."
Research shows clinical depression affects around one in four people and some of those people will eventually become suicidal.
There are approximately 5,000 suicides per year in the UK - significantly more than deaths following road accidents.
The team are currently sending letters to GPs around Oxford in search of volunteers for the course which is free of charge.