Roads, isolation and more schizophrenia hospital visits ^{CEFR B2}

In New York City, researchers found that urban communities isolated by roadways and traffic patterns had higher rates of schizophrenia-related hospital visits. They report that this association was independent from traffic-caused air pollution. The team used ZIP code-level analyses with annual counts from the New York State Department of Health for hospital visits related to mood, anxiety, adjustment and schizophrenia disorders. Community isolation was measured with a new Community Severance Index, which the researchers developed to capture the presence of major roads, traffic intensity and lack of pedestrian infrastructure such as sidewalks and crosswalks.

Marianthi-Anna Kioumourtzoglou led the index development and co-led the study; she is now affiliated with Brown’s Center for Climate, Environment and Health. Jaime Benavides of Brown University School of Public Health described the contrasting environment as one where cars are present but do not dominate, with robust pedestrian traffic, walkable routes and visible social life such as children playing and neighbors talking. Among the outcomes examined, the strongest and most consistent association was with schizophrenia-related visits, and the effect was similar across age groups.

The authors suggest several pathways by which isolation may harm mental health: reduced access to goods and services, fewer social contacts, discouraged walking and physical activity, and greater psychological stress from road safety concerns. They argue that reducing vehicle emissions alone may not be enough and that planners should move away from car dependence toward places that bring people together. Next steps include making the Community Severance Index generalizable to other large US cities and studying how extreme heat, air pollution and isolation together affect elderly mental health. The research was supported by the National Institute of Environmental Health Sciences and the National Institute on Aging.