I have begun a research project to test the effectiveness of day treatment of individuals with serious and persistent mental illness. The locations of the treatment centers are 2 small towns in rural western Minnesota. In reviewing the literature on day treatment and community support programs, I discovered that most in these studies were located in urban, highly populated areas.
The measure of success in these studies, usually the yearly rate of rehospitalization, were almost always several times higher than were the rates in the aforementioned rural Minnesota outcome study. What I have found is a direct correlation between low population density and low rates of rehospitalization of individuals with chronic mental illness. The rate of rehospitalization for the entire state of Minnesota in 1996 was 31% (Minnesota Department of Human Services, St Paul). All 3 counties that participated in the rural Minnesota study had lower population densities and lower rehospitalization rates than the statewide numbers. The most populous county, with 34,000 people, has a population density of 47.2 persons per square mile and a rehospitalization rate of 23.6% per year. The middle county, with 10,600 people, has a population density of 18.3 persons per square mile and a rehospitalization rate of 18.4% per year. The smallest and most rural county, with 6200 people, has a population density of 12.7 persons per square mile and a rehospitalization rate of 2.6% per year.
Husted JR. Population Density and Rehospitalization for the Seriously and Persistently Mentally Ill. Arch Gen Psychiatry. 1999;56(3):285. doi: