A new study by researchers at the University of Essex suggests that country walks may help reduce depression and raise self-esteem.

The study, which is the first ever to look at how green exercise, called "Ecotheraphy", specifically affects those suffering from depression, compared the benefits of a 30-minute walk in a country park with a walk in an indoor shopping centre.

A group of 20 members of Mind, England and Wales leading mental health charity, participated in the study.

While 71 per cent of the participants showed decreased depression levels after the country walk, 90 per cent reported increased self-esteem.

In contrast, only 45 per cent participants experienced a decrease in depression after the shopping centre walk, while 22 per cent said that they actually felt more depressed.

Nearly 50 per cent also felt more tensed, and 44 per cent reported decreased self-esteem after window-shopping at the centre.

In another study of 108 people with various mental health problems, the university researchers questioned them about their experience of ecotherapy.

While 94 per cent of the participants said that green activities had benefited their mental health and lifted depression, 90 per cent said that the combination of nature and exercise had the greatest effect.

"It is a credible, clinically-valid treatment option and needs to be prescribed by GPs, especially when for many people access to treatments other than anti-depressants is extremely limited," the Independent quoted Mind Chief Executive Paul Farmer as saying.

"We're not saying that ecotherapy can replace drugs but that the debate needs to be broadened," he added.

However, Paul strongly believes that ecotherapy may prove to be a boon for millions of people if prescribed as part of mainstream practice, as it is not only cheaper than anti-depressant drugs, but also has no side-effects.

The ecotherapy report is being launched at the Mind week, which is dedicated to raising awareness about the learning disability and the mental health charity.