单项选择题

The image of people jumping from windows after the stock market crash of 1929 graphically illustrates the pattern detected by researchers from the U.S. Centers for Disease Control and Prevention.
"The overall suicide rate rises and falls in connection with the economy," said lead researcher Feijun Luo, a health economist at the CDC’s National Center for Injury Prevention and Control.
"The strongest association between business cycles and suicides was among working-age people 25 to 64 years old," he said.
Co-author Dr. Alexander E. Crosby, a medical epidemiologist said economic hardship may trigger suicidal impulses in those already at risk of killing themselves.
"Suicide results from an interaction of a number of different factors," Crosby said. "Other studies have shown there is an association between suicide and unemployment, suicide and economic issues, and it can make vulnerable people more prone to be at risk for suicidal behavior," he said.
The report is published online April 14 in the American Journal of Public Health.
The researchers found suicide rates increased sharply during the Great Depression, during the oil crisis of 1973-1975, and the double-dip recession of 1980-1982.
But fewer people killed themselves during periods of economic expansion, such as the World War Ⅱ and years between 1991 and 2001, when the economy grew rapidly and unemployment was low.
To prevent economy-related suicides during economic downturns, communities might want to target programs toward working-age people, Crosby suggested. "Communities can have more support for those age groups that might be laid off," he said.
Providing job training, skills training and developing suicide prevention efforts "might be things communities could do," Crosby added.
David Rudd, dean of the College of Social and Behavioral Science at the University of Utah in Salt Lake City, agreed that those most likely to kill themselves in bad economic times are those already at risk of suicide.
"It’s fairly well established that upwards of 90% of those taking their own lives suffer from a diagnosable mental illness at the time, with the overwhelming majority not being in active treatment," he said.
The difference in impact across age groups is not a surprise, given that those hardest hit face the most pressing economic demands, Rudd added. "Prevention efforts need to focus on recognition and more effective response to psychiatric illness, particularly in primary care settings," he said.
According to Crosby, who are more likely to commit suicide for economic issues and unemployment