Although studies abound suggesting that green surroundings are good for both our mental and physical health most are based on some sort of self reporting so a recent study from Leipzig which used the frequency of anti depressant prescriptions as a metric is interesting. Of course whether or not an individual with depression is prescribed antidepressants depends on other factors, such as how depression is diagnosed and the medical accessibility or availability of treatment options but it is at least getting closer to an objective measure of depression. Probably not surprisingly to tree enthusiasts, the study concluded that living in an urban environment which included street trees, while having little effect on residents with relatively high socio economic status, significantly reduced the probability of being prescribed anti depressants amongs those of low socio-economic status.
And while on the subject of objective measures, another study from 2020 suggests that children raised close to green spaces have a higher IQ than those who are surrounded only by concrete. Once again these findings applied primarily to children of low socio-economic status. The study did not specify which form of green space although earlier studies have suggested that trees are more important as far as child development goes than just green spaces.
(As an aside, were you aware that the concrete used to create all of our urban deserts is the most widely used substance on earth after water? Producing 5% of our annual CO2 emissions…)
But, back to trees. If you would like to know more about the psychological benefits that trees can bestow upon you, read this article, with its attendant research, by Jill Suttie in a 2019 issue of Mind & Body.
- People walking in a forest (‘forest bathing’) experienced less anxiety, hostility, fatigue, confusion, and depressive symptoms, and more vigor, compared to walking in an urban setting, especially if they were already anxious.
- Gazing at even leafless trees in winter will improve your mood more than gazing at a load of buildings.
- People living close to trees have a brain structure better able to handle stressors.
- Spending time in forests appears to benefit the immune and the cardiovascular systems.
- Crime appears to be lower in heavily tree’d areas.
I have to thank the last of the Pesticide Action Network‘s Reassembling Our Cities presentations for alerting me to this research, primarily Ellen Miles who runs Nature is a Human Right and Paul Powesland of Lawyers for Nature.
Ellen’s group campaigns (they currently have a Change.org petition to the UN to Make Contact with Nature a Human Right) and leads guerilla gardening groups around cities.
Paul Powesland is a barrister who founded Lawyers for Nature to provide legal advice and support for environmental activists with an especial interest in protecting trees. They were involved in the long running and eventually successful campaign to prevent the felling of 1600 street trees in Sheffield.
Paul lives on a houseboat on the Roding River in Barking (see London’s Lost Rivers). His boat is moored in a small area which has effectively rewilded itself but is now open to the locals to enjoy and where he has already prevented at least one tree felling. If your tree is beside a public road or footpath and is threatened with imminent destruction, he says, go and stand on the path in front of it. The tree surgeons cannot fell it without getting at it, but they cannot remove you from a public highway.

Sure, being around trees does make (many) people feel better. Nonetheless, studies like this always ignore other studies that have found being around urban trees often results in increases in both allergy and asthma.
My point here is that “trees are not just trees.” There is a multitude of different species, different cultivars. Some trees are beautiful AND are not allergenic. At the same time, many popularly planted city trees are beautiful AND extremely allergenic.
*A last note, having asthma or severe pollen allergies does NOT reduce depression…just the opposite.
Plant more trees, yes, but plant allergy-friendly ones. We’ve already got way too many of the others.
You are totally right, of course, Tom – being around the wrong sort of trees will not help at all! And especially important in urban landscapes which are already very over populated with the wrong sort of pollen scattering males trees.