Schizophrenia risk has been linked to urbanization, but the underlying mechanism remains unknown. Green space is hypothesized to positively influence mental health and might mediate risk of schizophrenia by mitigating noise and particle pollution exposure, stress relief, or other unknown mechanisms. People who grew up without green spaces are 50% more likely to develop schizophrenia compared with those who grew up surrounded by greenery. The study was published in the journal Schizophrenia Research.
Green spaces include grassy fields, forests, or a field of corn. All types of vegetation count. They still do not understand all of the reasons for schizophrenia, so it's really exciting and important to have this information. Nordentoft studies the causes of schizophrenia and treatments and was not involved in the new study.
This is the conclusion of a new study, which is the first to find such a correlation. Even though a 50% higher risk sounds like a lot, it is worth remembering that schizophrenia still affects less than one percent of those studied and one percent among those who had grown up with few green spaces.
Satellite photos combined with psychiatric registers
In the new study, scientists from the Department of Bioscience and the Centre for register research at Aarhus University, Denmark, used satellite photos to map green spaces throughout Denmark between 1985 and 2013. Of those studied (943,027 people in total), 7,509 of them were diagnosed with schizophrenia. They can see that those with the least access to green spaces within 210 square meters of where they live, which is pretty close, have a higher risk of developing schizophrenia.
This does not mean that just because you did not have a view of trees or fields from your bedroom window as a kid that you will automatically develop schizophrenia in adulthood, but it is an important piece of the puzzle to understand all of the factors that can lead to the condition. Schizophrenia develops by a combination of many different factors, which increase the risk and ultimately lead to schizophrenia. Our surroundings are apparently one of these factors.
Previous research has shown that city dwellers are more at risk of schizophrenia, but scientists did not know precisely why. It could be related to a lack of green spaces. However, explaining this connection is still tricky.
Smaller studies have shown that having green spaces provides stronger social cohesion and that you're more likely to get out and exercise. This can have an effect on your psychological health. So perhaps it is an indirect effect of having green spaces.
Green spaces calm racing thoughts
Other studies have shown that children's cognitive development improves when they are surrounded by more green space, and similarly that people are less likely to suffer from racing thoughts and rumination a typical symptom of schizophrenia. Understanding the impact of greenery on human health is even more important at a time when people increasingly live in cities. The more they understand this, the better prepared we are to plan our cities.