On a January morning six years ago, Jonny Benjamin walked halfway across the Waterloo Bridge, in London, stepped to the edge, and prepared to jump. Benjamin, who was then twenty, had just been given a diagnosis of schizoaffective disorder; he felt that all the days ahead were doomed. As he was about to leap from the bridge’s walkway, a stranger approached him, and began to talk. The man, who was about the same age, asked Benjamin to join him for a cup of coffee. “It’ll get better, mate,” the stranger said. “You will get better.”

Benjamin didn’t jump. As the years went on, he forgot the name of the man who had persuaded him to go on living. This January, to help raise awareness of mental-health issues, Benjamin—with the support of celebrities like Stephen Fry, Boy George, and David Cameron—launched a social-media campaign to find the man he had nicknamed Mike. “I didn’t expect to find him,” Benjamin told the Guardian. “It felt like looking for a needle in a haystack. I couldn’t remember anything about him.” But millions of people shared the story online; the hashtag “FindMike” was among Twitter’s trending keywords in the United Kingdom and as far afield as South Africa, Australia, and Canada. The Good Samaritan’s girlfriend saw the plea on Facebook and encouraged her boyfriend to go public. He did, and the two men met once again—this time with a hug.

Mike is Neil Laybourn, a thirty-one-year-old native of Surrey who works as a personal trainer. He still walks over the Waterloo Bridge on his commute, a daily reminder of that day, six years ago, when he saved a man’s life simply by asking him to talk. The connection wasn’t even so hard: it turns out that the two men grew up ten minutes away from each other. But it was Laybourn’s basic sense of compassion, Benjamin said, that did the trick: “When he came along it burst the bubble of that world I was in. I felt faith, like I could talk to him.”

A week after Benjamin was reunited with Laybourn, Le Monde, the leading newspaper on the other side of the English Channel, published the results of a medical study of French fifteen-year-olds, which revealed that almost twenty-one per cent of girls and nine per cent of boys reported attempting suicide in the past year. That’s a shocking number, and it speaks to a global trend. In the United States, suicide rates have risen, particularly among middle-aged people: between 1999 and 2010, the number of Americans between the ages of thirty-five and sixty-four who took their own lives rose by almost thirty per cent. Among young people in the U.S., suicide is the third most common cause of death; among all Americans, suicide claims more lives than car accidents, which were previously the leading cause of injury-related death.

Last May, citing the “substantial” rise in suicide among the middle-aged, the Centers for Disease Control and Prevention described suicide as “an increasing public health concern.” That realization has begun to spread: in the same month, Newsweek ran a cover article called “The Suicide Epidemic,” noting that, around the world, self-harm takes “more lives than war, murder, and natural disasters combined.” In America, these numbers—which many experts believe are lower than the actual figures, owing to under-reporting—cannot simply be attributed to the toll of a long recession, or increasing gun ownership: clinical depression is also on the rise. Suicide rates declined in the nineteen-nineties, but since 1999 more Americans have killed themselves each year than in the one before.

Alan Berman, the executive director of the American Association of Suicidology and the president of the International Association of Suicide Prevention, has said that in the developed world ninety per cent of those who attempt suicide suffer from psychological ailments. “We have effective treatments for most of these,” Berman said last year. “But the tragedy is, people die from temporary feelings of helplessness—things we can help with.” The relentless intensity of those feelings has always been difficult to convey to those who have not experienced them: William Styron, in his powerful memoir, “Darkness Visible,” lamented the insufficiency of “depression” as a label for “the veritable howling tempest in the brain.” Styron, who checked himself into the affective-illness unit at Yale-New Haven hospital, lived to write an account of his suffering, but many others lack the wherewithal, or the capacity, to seek such help. This is why Jonny Benjamin now works with a British nonprofit called Rethink Mental Illness, whose mission is to provide support to those contemplating suicide—to help them in the same way that Neil Laybourn helped Benjamin walk away from the edge of a bridge.

In 2003, Tad Friend wrote in this magazine about the “fatal grandeur” of the Golden Gate Bridge, which had been identified as the “world’s leading suicide location.” The iconic status of the span, and its majestic view, seemed to draw jumpers to its walkway. “Several people have crossed the Bay Bridge to jump from the Golden Gate; there is no record of anyone traversing the Golden Gate to leap from its unlovely sister bridge,” Friend wrote.

A local California doctor named Jerome Motto told Friend that he has participated in several efforts to erect a suicide barrier on the bridge, after one of his patients killed himself there in 1963. But the jump that had most touched him took place the following decade. “I went to this guy’s apartment afterward with the assistant medical examiner,” Motto recalled. “The guy was in his thirties, lived alone, pretty bare apartment. He’d written a note and left it on his bureau. It said, ‘I’m going to walk to the bridge. If one person smiles at me on the way, I will not jump.’ ”

This, of course, is what Neil Laybourn did for Jonny Benjamin. Writing after their reunion, Benjamin said: