A sharp increase in suicide rates among middle-aged Americans in the years after 2007 is linked to economic troubles brought about by the financial crisis, according to a study published Friday in The American Journal of Preventive Medicine.

The number of Americans age 40 to 64 who take their own lives has risen by 40 percent since 1999, according to the U.S. Centers for Disease Control and Prevention. And suicide rates for the age group have picked up markedly since the onset of the Great Recession, according to the report.

The increase comes despite the number of suicides leveling off over the same time frame for other age groups.

Previous studies have linked the Great Recession to higher rates of suicide. For example, a 2014 study published in The British Journal of Psychiatry calculated that the Great Recession was associated with an additional 10,000 suicides in North America and Europe from 2008 to 2010.

But previous reports were based on data that was presented in aggregate, the authors of the new report wrote, so they wondered what would turn up if they were able to look at individual circumstances, in particular looking at the impact on middle-aged Americans.

“Middle aged adults are more likely than others to be family breadwinners and supporting dependents,” the authors of the study wrote.

Researchers examined data from the National Violent Death Reporting System, which shares detailed information from law enforcement and medical examiners about the circumstances behind all types of violent deaths, including a victim’s physical and mental health problems or financial troubles.

Looking specifically at the reasons middle-aged people committed suicide from 2005 to 2010, they found that suicides were attributed, in part at least, to external factors such as jobs, legal problems or financial troubles rose to 37.5 percent of all suicides in the age range in 2010, up from 32.9 percent in 2005.

While researchers stressed that this data was limited to suicide attempts that resulted in death, and that most of the suicides — 81 percent — involved personal factors such as mental health problems, the link to external factors was strong in the case of middle-aged suicides.

“I hope that this raises awareness about he potential impact of economic crises on mental health,” said Julie Phillips, a sociology professor at Rutgers and one of the authors of the study. “I think when there’s a natural disaster, we marshal help to health crisis counseling, and perhaps we need to think about a similar approach when dealing with an economic crisis.”

What’s more, researchers looked at the methods behind the suicides, they found that suffocation increased by nearly 60 percent from 2005 to 2010 among middle-aged people. That is compared with an increase of 18 percent for people age 15 to 39 and an increase of 27 percent among 65 or older.

While Phillips said researchers couldn’t fully explain that increase, it could be tied to a decline in gun ownership.

“Certainly the most common means of suicide has been firearms, and we have seen a decline in gun ownership during the study, so people might be resorting to other means,” she said.

She added that most suicides are attributed to multiple factors, so it’s difficult to tease out one singular reason.

“I think it’s interesting, and it invites much more research, but I would want to see it replicated with some other careful studies,” Dr. Eric Caine, a co-director of the Center for the Study of Prevention of Suicide at the University of Rochester Medical Center, said of the results.