In the United States and Denmark, nationwide epidemiological studies of children have shown green spaces in residential areas are linked to a lower risk of mental health issues later in life.
In the United Kingdom, similar studies have found children living in greener city neighborhoods have better spatial working memory. A long-term study among 3,568 students in London, between the ages of 9 and 15, has found those kids who spent more time near woodlands showed improved cognitive performance and mental health in adolescence.