Suicide rates are higher in rural counties, according to a new study, and the reason is firearm use by men.

The report, in the American Journal of Public Health, used data on 6,196 suicides of Maryland residents over age 15. They found that the rate of firearm suicides was 66 percent higher in the most thinly populated counties than in metropolitan areas with populations greater than a million. Non-firearm suicide rates in rural and urban counties were roughly the same.

Rates of firearm suicide by women were no different in rural and urban areas, but total suicides by women were 37 percent greater in urban areas.

Men accounted for about 80 percent of all suicides, and nearly 90 percent of gun suicides. The suicide rate in rural settings, the authors conclude, is primarily driven not by lack of access to mental health care or economic disparities, but by men’s preference for suicide by gun, and the wider availability of guns in rural areas.