Yet scientific research suggests that we’re overlooking one critical factor for optimum mental health: nature.

You might grumble skeptically at the notion that parks and plants make a real difference in our happiness, but the research is convincing. A pile of studies on the subject consistently points to a strong connection between green space and mental health. In general, scientists believe that experiences in “green space” can boost mental health by improving the immune system, encouraging physical activity and social interaction, limiting air pollution and noise that interferes with thinking, and restoring a frenzied mind to a state of calm.

Take a study published Monday in Proceedings of the National Academy of Sciences. The researchers used data from Danish health registries for more than 940,000 children born between 1985 and 2003, and analyzed their mental health outcomes in tandem with the green space surrounding their homes. They found that the relative risk for developing a psychiatric disorder in adolescence or adulthood was significantly higher — from 15 to 55 percent — for those surrounded by the least green space.

Even when the researchers controlled for parents’ age and socioeconomic status, family history of mental health, urbanization, and municipal socioeconomic factors (think average income, education, and unemployment where the child lived), green space continued to have a protective benefit on mental health. The strongest association between exposure to green space and increased risk of developing a psychiatric disorder showed up for those who had lived in downtown Copenhagen while the weakest was demonstrated in rural Denmark.

There are questions the study can’t answer, including whether people with a higher genetic risk for mental illness would be more inclined to choose denser urban areas, or whether unmeasured socioeconomic factors like higher crime rates and lower-quality green space could play a role in mental health outcomes. But this research begs us to consider anew how exposure to nature in an urban environment could enhance or hurt our mental health — and what we plan to do about that.

Kathleen Wolf, a research social scientist at the School of Environmental & Forest Sciences at the University of Washington who was not involved in the PNAS research, believes that this study and others like it prove that we need to take green space seriously in cities as a means for improving people’s every day quality of life and well-being.

Some might see trees and gardens as “nice, frilly things” to have around us, says Wolf. But she sees encounters with green space and nature as opportunities to prevent or diminish mental illness.

“Can we, by way of urban greening and other interventions, alleviate the pain and suffering before it happens?” says Wolf.

It’s a bold vision that may sound like it mistakes green space as a panacea for all that ails us, but Wolf is more realistic than that. She knows that greening alone won’t prevent every mental health condition, but she’s also confident that designing and creating public places, workplaces, schools, and parks around green space could significantly improve people’s quality of life and emotional well-being. Scientific research, she says, suggests that experiencing natural environments in urban settings help people recover from the constant low-grade stress of city life.

Though the importance of green space for mental health occasionally becomes a hot topic, thanks partly to scientific studies, it can’t compare to the popularity of talking about self-care or meditation. That’s because those pastimes can be customized by each individual (and commodified) with apps, workshops, and classes.

Getting more green space, on the other hand, can be a bureaucratic or logistical hassle. You have to learn who makes decisions about how parks are designed in your city or how to use public transportation to get to green space, a particularly grueling exercise for city-dwellers with little time or income. Sometimes, says Wolf, decision-makers and managers put parks, trees, or other green spaces in communities without engaging residents in order to learn what types of features would be convenient, practical, and culturally meaningful for them.

Tools like therapy and medication can be pricey, but are also critical for mental health. And given the barriers to creating and accessing green space, it’s no wonder people view the former as some of the only options for managing their well-being.

Given the evidence on the connection between nature and public health, Wolf says that the professionals who plan cities should create greening policies and programs so that everyone can enjoy access to nearby nature. She believes such features should be just as important in urban planning as transportation and housing.

Yet another study that highlights the link between green space and mental health is a timely occasion to remember that people aren’t solely responsible for nurturing their own emotional and psychological wellbeing. Those who plan the roads, parks, schools, and office buildings that surround us also play an important, if indirect, role as guardians of our mental health. And we should feel empowered to fight for our mental health by demanding what we deserve: green spaces with the potential to help everyone thrive.