Two studies link parks and poshness to lower depression and cognitive decline, for reasons still unclear.

As cities boom and high-rise living becomes the norm, planners might want to listen up to a new study that finds a childhood without green space increases the risk of mental illness.

The study, led by Kristine Engemann from the Department of Bioscience at Aarhus University in Denmark, used satellite imagery to measure vegetation around the childhood homes of nearly a million Danes born between 1985 and 2003.

The Landsat pictures were used to draw a 210 by 210 metre box around each person’s house at age 10, then calculate a greenery index. The study included people across the urban-rural divide, but only those whose long-term mental health outcomes were on record.

And here’s why you shouldn’t take your local park for granted.

As greenery round the childhood residence shrunk, risk of mental illness as an adolescent and adult went up. Kids who grew up in plots with the least vegetation had a 15 to 50% greater incidence of a range of psychiatric problems, including depression, eating disorders, anxiety and obsessive compulsive disorder.

The association held even when researchers adjusted results for potential confounds such as a family history of mental illness or social disadvantage.

The study is yet more evidence of a disturbing trend: cities seem to be bad for your mental health. Existing studies, the researchers write, show city folk have a 50% higher risk of psych disorders and urban kids are at double the risk of schizophrenia.

The burning question is why.

Read the full article at Cosmos magazine here