Cities are exciting places, full of cultural and educational opportunities, top quality medical care, and so much more. And, despite being disproportionately expensive, people pay a premium to live in major metropolitan areas. Unfortunately, as research into the health implications of urban living has revealed, living in cities may pose serious neurological risks – but why?
The Problem Of Air Pollution
Like traffic or crowded sidewalks, air pollution is an expected part of urban living, and while we obviously expect air pollution to impact lung health and, potentially, other organ systems, such as the skin, a recent study of elderly women living in areas with high levels of air pollution have increased rates of depression. This is particularly concerning, since exposure to air pollution late in life also speeds brain aging and increases the risk or dementia.
It’s not just the elderly who are at risk from air pollution exposure, of course. Children in districts whose schools retrofitted their diesel buses to reduce emissions showed improved academic performance, and air pollution is likely implicated in attention problems, as well, pointing to cognitive implications.
Mental Health Magnified
While air pollution is one cause of mental health issues in urban environments, there are many others. In fact, while there are a variety of chemical and genetic issues at play, ultimately individual experiences are the greatest determinant of mental health, and childhood stressors – sometimes measured using the Adverse Childhood Experiences (ACEs) – are generally considered most important. Though such events, which include abuse and neglect or parental separation, can happen anywhere, many ACEs, like witnessing violence in the community or having an incarcerated parent, are statistically more likely in urban settings.
As worrisome as ACEs are from a developmental and mental health perspective, many are preventable or at least remediable with proper intervention, which can improve outcomes for the most vulnerable children. Funding for neuroscience research on mental health can help clinicians determine best practices, allowing for early intervention programs and community supports.
From Symptom To Structure
When it comes to the impact of environmental factors like pollution and trauma on the brain, we have a lot of subjective measurements like mood reports, as well as the ability to measure effects like grades or memory. To more fully understand the impact of environment on the brain, however, we need to look at the organ itself.
General research into structural changes in mental illness shows substantial overlap between conditions, but we don’t yet know how much of that is environmental and how much stems from genetic similarities. However, early findings do show that individuals who grew up in cities have a harder time downregulating the amygdala, which is the part of the brain that registers stress; the same study also showed that those currently living in cities responded more negatively to negative feedback in the first place. These types of changes are only visible on functional MRI scans, since they are chemical, rather than structural.
It’s not tenable or desirable to evacuate cities in the name of cognitive and emotional well-being, but the more we learn about the link between urban environments and brain health, the more steps we can take to change the harmful aspects of cities. That’s the best way to make cities healthier for everyone who lives there, physically and emotionally.