By David Suzuki with contributions from David Suzuki Foundation Senior Public Engagement Specialist Aryne Sheppard.
For the most part, our brains didn’t evolve in cities. But in a few decades, almost 70 per cent of the world’s people will live in urban environments. Despite the prosperity we associate with cities, urbanization presents a major health challenge. Cities, with their accelerated pace of life, can be stressful. The results are seen in the brains and behaviour of those raised in cities or currently living in one.
On the upside, city dwellers are on average wealthier and receive better health care, nutrition and sanitation than rural residents. On the downside, they experience an increased risk of chronic disease, a more demanding and stressful social environment and greater levels of inequity. In fact, city dwellers have a 21 per cent greater risk for anxiety disorders and a 39 per cent increased likelihood of mood disorders.
A study published in Nature links city living with sensitivity to social stress. MRI scans show greater exposure to urban environments can increase activity in the amygdala, a brain structure involved in emotions such as fear and the release of stress-related hormones. According to the study, the amygdala “has been strongly implicated in anxiety disorders, depression, and other behaviours that are increased in cities, such as violence.”