Suicide has surpassed car accidents as the No. 1 cause of injury-related death in the United States, according to new research.

From 2000 to 2009, the death rate for suicide ticked up 15 percent while it decreased 25 percent for car wrecks, the study found. Improved traffic safety measures might be responsible for the decline in car-crash deaths. As such, the researchers said similar attention and resources are needed to prevent suicide and other injury-related mortality.

Death by unintentional poisoning, which includes drug overdoses, came in third behind car wrecks and suicide after increasing 128 percent from 2000 to 2009. The data from 2010 would push that rise in death rate even higher, to 136 percent, study researcher Ian Rockett told LiveScience in an email. Prescription painkiller overdoses might be to blame for this drastic rise. Recent research has shown that in some states painkiller overdoses may be responsible for mor deaths than suicide or car crashes.

"While I am going well beyond our data, my speculation is that the immediate driving force is prescription opioid overdoses," said Rockett, who is a professor at West Virginia University's School of Public Health. "There is much to be done in terms of both research and prevention."

The new study, published in the November 2012 issue of the American Journal of Public Health, also found that unintentional falls and homicide were the fourth and fifth causes of injury death, respectively. And overall, injury-related deaths were less common in females than males.

The research was based on data from the National Center for Health Statistics.

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