Depressive disorders are common mental health conditions, associated with social impairment and reduced quality of life. Depression presents in various clinical forms, with Major Depressive Disorder being the most severe and prevalent. This condition is characterised by the presence, for at least two weeks, of symptoms such as low mood, loss of interest or pleasure in leisure activities, psychomotor slowing, sleep and appetite disturbances, and difficulty concentrating.
Several factors may increase the risk of developing depression or worsen its course. These can be grouped into three main categories:
e.g. genetic susceptibility;
e.g. economic deprivation;
e.g. air pollution
In the environmental category, numerous studies over the past 15 years have demonstrated a link between concentrations of certain air pollutants and the severity of depressive symptoms.
A previous study by our research group showed that high levels of nitrogen oxide and airborne particulate matter (PM) are associated with increased severity of depressive illness—particularly in cold weather and among hypersusceptible individuals (such as those with inflammatory conditions like diabetes).
Having established the harmful effects of air pollution on mental health, researchers have turned to exploring which aspects of the natural environment might instead have a positive influence on the course of depressive disorders.
Increasing evidence now supports the protective role of green spaces in reducing the incidence of depressive disorders.
Green spaces have been analysed not only in terms of surface area, but also vegetation quality, usability, and proximity to one's residence.
Existing studies have examined these relationships both in the general population and in groups at higher risk of mood disorders, in particular:
Research has also investigated the mechanisms through which green spaces may improve mental health. The main mediating factors identified include:
Scientific literature consistently indicates that the presence of parks near one’s home may reduce both the risk and severity of depressive symptoms.
Associate Professor of Occupational Medicine, Department of Clinical and Community Sciences, University of Milan. Occupational Physician, "Luigi Devoto" Occupational Health Clinic, Occupational Medicine Unit, IRCCS Ca’ Granda Foundation, Ospedale Maggiore Policlinico
Postdoctoral Research Fellow, Department of Clinical and Community Sciences, University of Milan
Coordinator for Dissemination Strategy and Interpretation of Mental Health Data. Associate Professor of Psychiatry, Department of Medical-Surgical and Transplant Physiopathology, University of Milan. Consultant Psychiatrist, Department of Neurosciences and Mental Health, IRCCS Ca’ Granda Foundation, Maggiore Policlinico Hospital
Full Professor of Forest Management and Silviculture, University of Bari Aldo Moro
This study analyzes the relationship between air pollution and content of neuron-derived extracellular vesicles in a population of patients with depression.
This study analyzes the effect of green spaces on the severity of Major Depressive Disorder, highlighting a protective effect.
This study analyzes the relationship between air pollution and content of neuron-derived extracellular vesicles in a population of patients with depression.
This study analyzes the effect of green spaces on the severity of Major Depressive Disorder, highlighting a protective effect.
