A federal report released Thursday revealed that suicide rates among U.S. middle school students doubled from 2007 to 2014, Reuters reported. And for the first time, those numbers were higher than those of youths aged 10 to 14 who died in car crashes.

The steady rise in middle school suicides, from an annual rate of 0.9 to 2.1 per 100,000, came as traffic deaths among the same age group declined to 1.9 per 100,000, according to the Centers for Disease Control and Prevention in Atlanta.

The motor vehicle mortality rate reported for 2014, the latest year that such data was available, marked a 60 percent decline from 1999, the first year statistics were kept.

In aggregate numbers, 425 young people 10 to 14 years of age committed suicide in 2014, compared with 384 who died in automobile accidents that year, according to the CDC.

In 1999, the rate of middle school students killed in car crashes was four times higher than the rate among those who died from suicide that year.

"Any rise (in youth suicides) should be of concern, there's no doubt," Mark Kaplan, a professor of social welfare at UCLA, told Reuters in a telephone interview. "In time we might uncover some reasons, but a cautionary note (is) not to rush to any conclusions from this," Kaplan said.

The underlying causes of suicide are highly complex, making it difficult to explain the trends documented by the CDC, he added.

"Kids spend a lot of time at school ... it's where they live their lives," David Jobes, who heads the Suicide Prevention Lab at Catholic University in Washington, D.C., told NPR. "Suicide prevention has been focused on schools for a long time because it's a place where kids are and where a lot of problems can manifest."

Jobes recommends resources from the American Foundation for Suicide Prevention that are specific to schools and can assist educators.