Adults who exercise for 75 minutes a week are 18% less likely to be depressed –

According to a new study, as little as 75 minutes of brisk walking per week can reduce the risk of depression.

The World Health Organization recommends that everyone get at least two and a half hours of exercise every seven days.

But researchers from the University of Cambridge, England, found that adults with half that amount were one-fifth less likely to have depression, while those who had it had a 25% lower risk.

Scientists have suggested that even a small amount of exercise can have a “significant benefit” to a person’s mental health.

Exercise can help with depression because it triggers the release of endorphins — feel-good chemicals — and improves body image perception, they said.

Depression is a leading cause of disability worldwide, with patients struggling with prolonged unhappiness and hopelessness.

An estimated one in five American adults — or 40 million people — suffer from the condition.

Some research has suggested that physical activity may help prevent depression and may even be as effective as antidepressants.

In the most recent meta-analysis published in JAMA Psychiatry, researchers analyzed data from 190,000 adults, including 28,000 with depression.

The 15 studies used controlled activity levels of all participants and whether they had had depression for at least three years.

Those who did half the recommended amount of exercise were compared to those who did not.

The vast majority of studies used were conducted in developed countries, six in the United States, six in Europe, and one in both Australia and Japan.

A study was conducted in the developing world by considering India, Ghana, Mexico and Russia.

The results showed a rapid decrease in the rate of depression even at low activity levels.

But as participants became more active, the mood-boosting returns steadily declined.

In the study, led by Dr Matthew Pearce, an epidemiologist, the scientists noted: “Significant mental health benefits can be achieved with physical activity, even below public health recommendations.

“There was (was) an additional benefit of meeting the minimum goal, but otherwise limited additional benefit.”

They added: “Assuming a causal relationship, one in nine cases of depression could have been prevented if everyone in the population were active at the current level of health advice.”

“Multiple mechanisms” triggered by exercise are likely to lead to lower depression levels, the researchers said.

They suggested that exercise could alleviate symptoms and promote feelings of well-being by triggering the release of endorphins in the brain.

It can also improve one’s self-image and body image and encourage more social interaction.

But they cautioned that the associations may actually mean that people with depression are less likely to exercise rather than benefit.

“It is still possible that the observed associations … exaggerate the role of physical activity,” they said.

The study was observational and could not exclude another factor that caused a decrease in depression rates in people who exercised more.