Transcendental meditation, the technique of achieving a state of "restful alertness" popularised by The Beatles 40 years ago, may be an effective treatment for depression in older people, scientists have found.

Two studies of more than 100 patients at risk of heart disease showed that those who practised the technique experienced a reduction in depressive symptoms of up to 48 per cent. Depression increases the risk of a heart attack even at moderate levels.

The small studies were led by a researcher from the Maharishi University of Management in Iowa in the United States, which was founded by the Maharishi Mahesh Yogi, who introduced Transcendental Meditation (TM) to India in 1955 and subsequently promoted it across the world.

Although the Maharishi University exists to promote Transcendental Meditation, the research was conducted with the Charles Drew University in Los Angeles and the University of Hawaii, and the findings were supported by other academics. They add to a growing body of evidence about the health benefits of the technique.

"These results are encouraging and provide support for testing the efficacy of Transcendental Meditation as a therapeutic adjunct in the treatment of clinical depression," said Hector Myers, professor of clinical training at the department of psychology at the University of California in Los Angeles.

Gary Kaplan, associate professor of neurology at New York University, said: "Any technique not involving extra medication in this population is a welcome addition. I look forward to further research on the Transcendental Meditation technique and prevention of depression in other at-risk populations."

Transcendental Meditation became popular in the UK after The Beatles visited the Maharishi at his ashram in India in 1968. Other stars who beat a path to the Maharishi's door included Donovan, the Welsh troubadour, the actress Mia Farrow and Mike Love of The Beach Boys. The movement received a boost two years ago when Donovan teamed up with the cult film director David Lynch to launch a campaign encouraging children to meditate in school.

Lynch donated millions to the David Lynch Foundation for Consciousness-Based Education and described the difference it made to his own life. "When I started meditating I had a real anger in me, and I would take this out on my first wife. Two weeks after I started meditating, this anger lifted," he said.

About 6 million people worldwide practise Transcendental Meditation, according to the movement's official website. The technique involves a form of concentrated attention in which the mind is turned inward and focused on a single point of reference. This is achieved by uttering the mantra, a word given to the student during the initiation ceremony which is chanted silently over and over.

The aim is to empty the mind of thoughts, feelings and fantasies, not by blocking their intrusion, which is impossible, but by observing them as they intrude and then always returning to the central task of attending to the mantra. In this way a state of "restful alertness" is achieved. Scores of scientific studies on the technique have been published since the 1970s, a number of which have shown benefits in lowering stress, blood pressure, cholesterol, smoking, drinking and anxiety. In 2005, The American Journal of Cardiology reported that among 202 patients with raised blood pressure who were followed for 18 years, those who practised TM had a 23 per cent lower death rate.

In 2006, a study in Archives of Internal Medicine found patients who practised the technique for 16 weeks had improved blood pressure, insulin resistance and nervous system. The National Institutes of Health in the US has found that people practising meditation have lower breathing and heart rates yet possess "higher EEG coherence" – indicating greater concentration and alertness.

The Maharishi travelled the world for decades before establishing a headquarters for his global activities in Vlodrop, a town in the Netherlands, in 1990. In 2005 he ordered his followers to stop teaching the technique in Britain in protest against Tony Blair's support for the US during the Iraq war and the British electorate's failure to unseat him at the general election. He said there was no point in wasting the "beautiful nectar" of TM on a "scorpion nation". The ban has since been lifted.

The authors of the latest study say that if the benefits of Transcendental Meditation in depression are confirmed, the technique could be of value to millions. One in five elderly people are thought to suffer from depression and half are undiagnosed by their family doctor. Drugs and therapy have a useful but limited effect.

Take a deep breath... TM facts and figures

* The Maharishi, who died in 2008, believed that the spiritual wellbeing of the world would be transformed if everyone spent 20 minutes each day meditating.

* The technique is claimed to reduce stress and anxiety and to offer a way of dealing with unpleasant emotions.

* Course fees are: £590 for individual income over £40,000, £490 for individual income over £25,000, £390 for individual income under £25,000 with concessions of £290 for students, unemployed and retired people, and £190 for students under 18.

* Instruction begins with a short ceremony and then the student learns and begins practising the technique. In the UK there are 80 official TM teaching centres.

* Some TM teachers have become concerned about the cost and have left the organisation to offer instruction on their own.

* John Lennon fell out with the Maharishi and wrote a song, "Sexy Sadie", about his supposedly materialistic ways.