As the world’s urban population surges toward 70% by 2050, mental health issues like anxiety and depression are becoming increasingly urgent public health concerns. These issues are already more common in cities. A new study by the Stanford University–based Natural Capital Project (NatCap) offers a hopeful solution: nature.
Published in the journal Nature Cities, the research reveals that spending even brief, stationary time in nature-rich urban environments significantly improves mental health. This improvement is especially notable by reducing symptoms of depression and anxiety.
Big Implications for City Planners and Public Health
The research is now being integrated into NatCap’s globally-used InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs) software. This software serves as a modeling tool for urban planners. For the first time, mental health impacts will be included. These impacts are considered alongside traditional ecosystem services like carbon capture, air purification, and temperature regulation.
“We are working to translate the effect size we found into intuitive indicators. These indicators can be used by decision-makers,” said Yingjie Li, NatCap postdoctoral scholar and lead author. “For example, if a city has 20% tree cover, how many mental health cases could be avoided by increasing it to 30%?”
Future versions of the model will even estimate potential avoided healthcare costs. This offers policymakers data-driven incentives to invest in urban greenery.
What Makes This Study Stand Out
While previous studies have shown a correlation between nature and mental health, this new analysis goes further. The Stanford team collated results from 78 field-based studies with 5,900 participants, based on randomized controlled trials or pre-post intervention studies—a robust standard of evidence.
“Most previous research couldn’t infer causality or compare different types of urban nature,” said Anne Guerry, NatCap’s chief strategy officer and senior author. “This study helps fill that gap with high-quality, generalized findings.”
What They Found: Forests, Stillness, and Youth
Urban forests were the most effective, especially in reducing symptoms of anxiety and depression. Passive time such as sitting quietly in nature was more effective for reducing negative outcomes like depression than active exercise. However, both forms were equally beneficial for boosting positive emotions like vitality and alertness.
Young adults (under 25) saw stronger mental health gains. This is an important insight since most mental illnesses first emerge before age 25.
Participants in Asian countries experienced greater benefits, possibly due to stronger cultural associations with nature, which may amplify psychological responses.
Designing Healthier Cities: From Forests to Pocket Parks
The study’s results have clear design implications for urban areas:
- Large urban parks and forests remain essential.
- Smaller pocket parks, tree-lined streets, and green rooftops can expand access to mental health–boosting nature across neighborhoods.
- Even views of nature from windows or quiet zones with natural elements offer benefits.
- Community activities like guided meditation sessions in parks are low-cost, high-impact interventions that could be widely adopted.
Nature as Therapy – A Personal Note from the Researcher
Beyond the science, lead researcher Yingjie Li says the study changed his personal habits. “I walk to the office more often now and pay more attention to the birds and plants I pass,” he said.
“It’s made me realize that urban nature isn’t just good for cities – it’s good for us.”
Nature Is a Mental Health Prescription Cities Can Afford
As urban life becomes more stressful, access to nature emerges as a powerful, evidence-based solution for mental wellness. This research adds to a growing consensus: restoring and protecting urban nature is not just good for the environment – it’s critical for our mental health.
Urban planners, public health officials, and community leaders now have new data tools. They also have actionable strategies to create healthier cities—one tree, park, or quiet bench at a time.
