Suicide has surpassed motor vehicle accidents as the leading cause of injury deaths, according to a West Virginia University study published online Sept. 20 by the American Journal of Public Health.

Using data from the National Center for Health Statistics, the study found that suicide mortality rates had increased 15 percent from 2000 to 2009, while unintentional motor vehicle accident mortality rates decreased 25 percent. The dramatic increase in suicide mortality is prompting researchers to question the possible causes of the spike.

Ian Rockett, director of Educational Programs in the Department of Medicine at WVU, said the state of the economy might have influenced the increased suicide rates, which jumped significantly in 2009.

“It’s hard to tell what the reasons are for sure,” Rockett said. “But I’d have to say that the economy absolutely plays a role.”

Carol Gall, co-chair of the Illinois Suicide Prevention Alliance, said military suicides have also played a significant role in the increase.

“We are seeing people coming back from war with a whole host of stress disorders, and the signs are not being recognized,” Gall said. “These people are often taking their own lives.”

There were more than 1,100 military suicides from 2005 to 2009, according to a 2010 Department of Defense report. A second report showed that in 2009 alone, 707 veterans committed suicide, and 10,665 more unsuccessfully attempted to take their own lives.

The study also showed a significant spike in the unintentional poisoning death rate.

Deaths from unintentional poisoning, which include drug overdose, increased 128 percent. Rockett said the increase could be related to the influx of prescription drugs entering the market from 2000 to 2009. He added that most unintentional poisoning deaths were due to overdose.

Rockett said it is difficult to distinguish suicide from unintentional poisoning unless the deceased person leaves an expression of intent, which is why the unintentional poisoning rate eclipsed the suicide increase. “I was particularly interested in the poisoning deaths because I think a lot of them are misread suicides,” Rockett said. “If they aren’t, then many of them certainly reflected self-harm.”

Suicide is an epidemic in the U.S., killing aproximately 40,500 people annually, according to the study.

The Illinois Suicide Prevention Alliance records more than 1,000 suicides annually in the state, a figure confirmed in Rockett’s study.

Bob Anderson, chief of mortality statistics for the NCHS, said the numbers represented in Rockett’s study are important because the data it provides are vital for Rockett’s research.

“This is one of the most used data sets within the federal government, as well as for nonprofit organizations and academia,” he said.

Rockett said research on disease as a cause of death far exceeds the amount of attention paid to suicide and injury deaths, which was his motivation for conducting the study. He also said more funding should be provided to help prevention measures for injury-related deaths.

Gall believes every suicide is preventable, and it is up to everyone to spot potential suicides. Recognizing early warning signs is critical to helping people cope.

“No one wakes up telling themselves they want to die,” she said. “There is something else going on there, so everyone—friends, family, and society—has to help people get to a place where they can see a light and a way out of the pain they are feeling.”