OVER the last decade, the United States has become a less violent countryin every way save one. As Americans commit fewer and fewer crimes against other people’s lives and property, they have become more likely to inflict fatal violence on themselves. In the 1990s, the suicide rate dipped with the crime rate. But since 2000, it has risen, and jumped particularly sharply among the middle-aged. Thesuicide rate for Americans 35 to 54 increased nearly 30 percent between 1999 and 2010; for men [...]