Green spaces and mental health – a study conducted by Cédric Galera
RetourA team of European researchers and members of the BPH,
led by Cédric Galera, studied the impact of the presence and accessibility
of green spaces on mental health.
This study provides findings that could inform public prevention policies, particularly those aimed at the most disadvantaged populations
who are more exposed to these difficulties
Study results are clear: people with the least exposure to green spaces have a higher risk of psychological distress.
Using robust scientific methodology and criteria, Cédric Galera’s team highlights the protective effect of green spaces, which is particularly pronounced among the most vulnerable populations, with a reduction in psychological distress of around 30%.
Reducing mental health inequalities: a major challenge
Mental health, a priority national research topic in 2025, is closely linked to social inequalities.
The most disadvantaged populations are more exposed to psychosocial stress factors and often have limited access to green spaces.
Previous studies had already established a correlation between access to green spaces and well-being, but without assessing the reduction in mental health inequalities between social groups.
To answer this question, Cédric Galera, epidemiologist, university professor, hospital practitioner in child psychiatry and head of our BPH-HEALTHY team, has teamed up with European researchers such as Marie Navarro, former BPH doctoral student at the University of Groningen in the Netherlands, Francesca Bentivegna and Eirini Flouri from University College London in the United Kingdom, as well as Charline Galesne and Noelia Retuerto from BPH.
Together, they sought to determine if the presence of green spaces helps to limit social inequalities in terms of psychological distress, and to provide data that could inform public decisions on urban planning and prevention.
A large-scale longitudinal study and a myriad of exposure factors leading to conclusive results
To obtain these results, researchers led by Cédric Galera used data from the Millennium Cohort Study (children and parents), which collects data from a large representative sample of the British population, with more than 25,000 adults followed between 2003 and 2016. Participants were followed longitudinally for 11 years, combining interviews and repeated surveys:
- Psychological distress was measured with the Kessler scale (K6), a tool for identifying symptoms of depression and anxiety
- Participants were classified according to their level of exposure to green spaces around their place of residence throughout their lives
- The analysis took into account numerous socio-economic and environmental factors such as poverty level, education, ethnicity, age, gender, physical health, urbanity and air pollution.
The results show that people living in environments with low vegetation cover have higher levels of psychological distress and conversely, demonstrating a significant effect of green spaces on mental well-being.
This protective effect appears to be greater among populations living in precarious situations. These spaces are conducive to activities that have positive effects on mental health, such as physical activity and social interaction, while limiting pollution and other urban nuisances that can be sources of stress. Thus, a living environment that offers access to this type of environment would help reduce social inequalities in mental health.
This research opens up important perspectives for public policy on health and urban planning. The integration of green spaces in areas where disadvantaged populations live would help to combat these inequalities.
Cédric Galera would now like to extend this research to children and adolescents in order to gain a better understanding of the impact of the environment throughout life.