What you've got there from the sun on your face is a massive boost of serotonin!" says Alison Greenwood, founder of Dose of Nature, the charity successfully prescribing time outside as a treatment for mental health. Dose of Nature has already delivered 1,500 one-to-one courses and is outperforming standard NHS talking therapies, boasting a recovery rate of 64% compared with the health service's 50%, and a reliable improvement rate of 86% compared with 69%. Unlike most green social prescribing schemes, clients are referred directly by their GPs. "Our nature prescriptions are a genuine alternative to medication and more traditional psychological therapies," Greenwood says. The key, she says, is the rediscovery of something very old: "The idea that nature is good for our mental health and wellbeing has been around for millennia. We evolved outside, under the sky, [and so] we are animals that are caged most of our time, in schools or cars or offices or homes. As soon as we get outside, we're free." There are two key parts to the Dose of Nature prescription: helping people get outside and, once there, to start noticing nature to calm their minds and bodies. As well as the serotonin-boosting sun and the phytoncides that can decrease stress hormones, studies have shown that natural sounds such as water, wind and birdsong improve mood. The fractal patterns of nature have been shown to aid recovery from stress and boost alpha waves in the brain.