It is well-documented that human mental health emerges from a complex interplay between genetic, psychological, lifestyle, and other factors. In addition, people are also exposed to numerous environments.
These environmental exposures (e.g Green space, noise, air pollution, weather conditions, housing conditions) might trigger mental disorders or be protective factors, facilitating stress reduction, mental recovery, etc].
“Environmental exposure” is understood in the broadest sense, comprising natural (e.g., park, bodies of water, weather), social (e.g., capital, cohesion), and built environmental exposures (e.g., urbanicity, intersection density, land use mix). Although some environmental factors—e.g., air pollution and green space—have already received broad attention in scientific debates, others have received very little, resulting in a tentative and partly inconclusive understanding of the environment–mental health relationship.
Mental illness contributes significantly to the global burden of mental disorders (i.e., 13% disability adjusted life-years lost). It is therefore important to grasp how and to what extent environmental exposures affect mental health outcomes. In the past year, 20% of all adults worldwide suffered from a mental disorder.
Mental disorders have a lifetime prevalence of two out of seven adults and will continue to remain a leading cause of disease burden. Such disorders have devastating consequences for people’s quality of life and represent striking challenges for health systems as a whole. Thus, the reduction of mental disorders is a health priority in both developed and developing countries.
The geographic context of individuals is a central construct in assessing the contribution of environmental exposures to people’s mental health. While residential neighborhoods are frequently thought to represent an environmental context, this approach is increasingly critiqued because it assumes that people are immobile and exposed only to their residential neighborhoods.
As this seems to be too restrictive an assumption, mobility-based environmental exposure assessments in mental health research have been put forward as methods that represent exposures more accurately. Such approaches highlight the importance of exposures that people experience throughout the day and over their lifetime.