Going for a walk could help beat depression, the mental health charity Mind has announced.
The claim is part of the charity's latest report into the green agenda for mental health.
It calls this new phenomenon 'ecotherapy', which it wants to become a clinically-valid treatment for mental health problems.
Ecotherapy involves getting outdoors and getting active in a green environment. Examples include walking, sport or gardening.
The charity's research found that 71 per cent of those involved in the studies report a decrease in depression after a green walk, while 22 per cent found depression increased after an urban walk.
The charity feels ecotherapy offers an alternative to prescribing medicines for depression and provides a more immediate response than the up to four year referral for Cognitive Behavioural Therapy.
Paul Farmer, Mind's chief executive, said: "Mind sees ecotherapy as an important part of the future for mental health. It's a credible, clinically-valid treatment option and needs to be prescribed by GPs, especially when, for many people, access to treatments other than antidepressants is extremely limited.
"We're not saying that ecotherapy can replace drugs but that the debate needs to be broadened."