By Steven Reinberg

HealthDay Reporter

THURSDAY, May 2 (HealthDay News) -- The number of middle-aged Americans who have committed suicide has risen sharply in the past decade, federal health officials reported Thursday.

Experts aren't sure why the jump in deaths has occurred, but point to the recession as a possible contributing factor.

According to the U.S. Centers for Disease Control and Prevention, suicides among those aged 35 to 64 have risen by 28 percent since 1999 -- from 13.7 suicides per 100,000 people that year to 17.6 per 100,000 in 2010.

More Americans now commit suicide than are killed in car accidents. In 2010, the CDC reported, 33,687 people died in car crashes, but 38,364 took their own life.

"We have known about this trend for a while now, the CDC is merely documenting it," said Lanny Berman, executive director of the American Association of Suicidology, who was not involved with the report.

Why the rate has risen so dramatically among the middle-aged isn't clear, Berman said. "I and most of my colleagues are dumbfounded to explain it," he said.

"The best we can come up with is maybe this is the group most likely to be affected by the recession and unemployment and [home] foreclosure," Berman said. "It affected suicide rates both nationally and internationally."

What isn't known, however, is how many of those who took their lives were having financial problems, Berman said. Whether the recession is the actual cause will take years to unravel. "All we can guess at now is association," he said.

Thomas Simon, deputy associate director for science in the Division of Violence Prevention at the CDC's National Center for Injury Prevention and Control, said one possible explanation for the increase in the suicide rate in this age group is that it includes the baby boom generation.

"Historically, we have seen high rates of suicide in that [group of people] at earlier ages in their lives in adolescence and young adulthood," he said.

In addition, the burst of the dot-com bubble and the recession may have played a role, Simon said. "Another explanation is the increase in prescription drug abuse and prescription overdose deaths and the risk of suicide that comes from prescription drug overdose and abuse," he said.

"Suicide is an important public health problem across the lifespan," Simon added. "Traditionally we have invested in prevention for adolescents and young adults and prevention for older adults. What we are seeing now is suicide is the fourth leading cause of death for the middle-age group. We need to better understand how to address the needs of middle-aged adults so that we can prevent suicide."

Suicide rates for those younger people aged 10 to 34, and seniors aged 65 years and older did not change significantly over the study period, the CDC researchers noted.

The report was published in the May 3 issue of the CDC's journal Morbidity and Mortality Weekly Report.

Berman believes a lot needs to be done to identify those at risk and get them help. "People at risk are help-able, but we have to get them into help," he said. "Most suicides are preventable."

CDC Director Dr. Tom Frieden said in an agency news release: "Suicide is a tragedy that is far too common. The stories we hear of those who are impacted by suicide are very difficult. This report highlights the need to expand our knowledge of risk factors so we can build on prevention programs that prevent suicide."

According to the report, the increases in middle-age suicides were particularly significant among whites (up 40 percent), and American Indians/Alaska Natives (up 65 percent).

The most common means of suicide for both men and women were hanging/suffocation, poisoning and guns, all of which showed an increase, the CDC found. Guns and hanging/suffocation were the most common method of suicide among middle-aged men, while poisoning and guns were the most common among middle-aged women.

Suicide rates increased in all states and the increases were statistically significant in 39 states, according to the report.

Other findings:

The biggest increases in suicide rates were among people aged 50 to 54 years old (48 percent) and 55 to 59 years old (49 percent).

Suicide rates rose by 23 percent or more in all four major regions of the country.

Suicide rates increased 81 percent for hanging/suffocation, 24 percent for poisoning and 14 percent for guns.

To collect the data the CDC relied on its web-based Injury Statistics Query and Reporting System.

More information

For more information on suicide, visit the U.S. National Library of Medicine.