In the days after her son Graham hanged himself in his dormitory room at Hamilton College (NY), Gina Burton went about settling his affairs in a blur of efficiency, her grief tinged with a nagging sense that something did not add up.  She fielded requests and sympathy notes from the college, promising the dean of students a copy of his obituary “so you can see how special Hamilton was to him.” This was why his suicide “makes no sense,” she added in a puzzled aside. But two weeks later, she read her son’s journal and everything changed. Mr. Burton, a sophomore, wrote that he was flunking three of his four classes and called himself a “failure with no life prospects.”