Atlantic Cities reports on research indicating an association between suicide and lower density, in an article entitled “The Unsettling Link Between Sprawl and Suicide.” Actually, there’s no reason to be unsettled, at least with respect to urban areas and their densities. The conclusions apply to rural areas, not urban areas.
Above the 300 persons per square kilometer, or 780 persons per square mile, the authors found no association. The authors of the study note, “above this threshold … the suicide rate remains fairly constant."
The US Census Bureau standard for urbanization is 1000 people per square mile or more, which is similar to the international standard of 400 persons per square kilometer. Even the suburbs of extremely low-density Atlanta and Charlotte have to reach the 1,000 persons per square mile threshold to be in the urban areas.
This research, while interesting, has nothing whatever to do with the urban form.