Mood enhancer: go down to the woods today

Spending more time 'forest bathing' can have a positive effect on depression. Rob Penn on what we owe trees

In autumn our woodlands are at their most enchanting. The sunlight angles gently in to create a changing mosaic of gold and brown; leaves twist and stall as they fall to the floor; branches chatter in the strengthening winds. It is the time of year when trees seem keenest to communicate with us, and when our bond with them is most vital.

The polymath American biologist EO Wilson first propounded his theory of biophilia - that we have a deep affiliation with other forms of life, like trees, which is instinctive and rooted in our biology - in the mid-80s. Around the same time, Professor Roger S Ulrich completed one of the first and best-known studies in the interdisciplinary field now known as environmental psychology. Ulrich's conclusion - that patients recovering from surgery in rooms with a window facing natural surroundings took less medicine for pain relief than patients with a window facing a brick wall - was groundbreaking.