Heroin use — which has been at the epicenter of a ruthless and relentless opioid epidemic sweeping the country — has increased fivefold over a decade, and dependence on the drug has tripled, researchers say.

A major study released Wednesday found that the sharpest increase in heroin use and addiction was among young white men with lower education and income levels.

The findings come as much of the focus surrounding the opioid crisis has been on the mortality rates among middle-aged white women since the turn of this century.

But researchers now say younger white men are being hit even harder — at least by heroin.

In fact, men ages 25 to 44 accounted for the highest heroin-related death rate (13.2 per 100,000) in 2015 — a 22 percent rise from the previous year, according to the Centers for Disease Control and Prevention.

Silvia Martins, the lead author of the new study, said increases in heroin use and addiction might be related to several factors, including prescription opioid abuse and market forces that favor cheaper alternatives to pills — such as heroin.

‘‘We saw that most of them had already used prescription opioids,’’ Martins, associate professor of epidemiology at Columbia University’s Mailman School of Public Health, said in a phone interview. ‘‘We saw that in 2001-2002, only 36 percent of white heroin users reported they had already used prescription opioids before. Now, more than half of them — 53 percent of them — said they had used prescription opioids before. So we believe there is a link to the prescription opioid epidemic.

‘‘Other potential reasons for that are the fact that heroin has become cheaper in recent years in the US.’’

Or, as Drug Enforcement Administration spokesman Rusty Payne said, ‘‘The world is filled with addicts who got a legitimate prescription for an opioid and then became dependent on that and continued long after their recovery. Pill addiction is extremely expensive, so they move to heroin because it’s cheaper and easier to get.’’

Payne added that the DEA is ‘‘seeing a lot of the traffickers who have substituted fentanyl for heroin, and so it’s just a vicious cycle of addiction we’ve seen with a lot of people.’’

The study, published in the journal JAMA Psychiatry, looked at data from two nationally representative household surveys from 2001-2002 and 2012-2013, analyzing responses from nearly 80,000 respondents. It showed that the number of people who reported using heroin at some point in their lives has climbed over the decade from 0.33 percent of the adult population to 1.61 percent, or about 3.8 million Americans.

The number of those who met the criteria for heroin use disorder, or addiction, more than tripled from 0.21 percent in 2001-2002 to 0.69 percent in 2012-2013.

Researchers say they also discovered a widening of the gender gap among users.

‘‘There are more men than women that are heroin users and that also have problems like heroin use disorder,’’ Martins said. ‘‘And that is different from what we see happening with other drugs and alcohol, so that was a surprising finding.’’

The research also revealed that the most notable increases were among whites, climbing from 0.34 percent to 1.9 percent over the decade, as well as among those with lower levels of education and income.

In the few years since the survey ended, the opioid epidemic has tightened its grip on an expanding portion of the US population.

Synthetic opioids — including heroin and its deadlier cousin fentanyl — are the main drivers of overdose deaths across the United States, according to the CDC.

Opioid deaths have continued to spike, with more than 33,000 fatalities across the country in 2015 — the highest figure in recent history, according to data released by the CDC. As The Washington Post’s Christopher Ingraham reported, that marked an increase of nearly 5,000 deaths from 2014. Deaths involving synthetic opiates, such as fentanyl, rose by nearly 75 percent from 2014 to 2015.

Nearly 13,000 people died of heroin overdoses that year, according to the data.

On Wednesday, President Trump signed an executive order creating a commission to deal with the escalating epidemic.

The commission, which will be led by New Jersey Governor Chris Christie, a Republican, will work to ‘‘combat and treat the scourge of drug abuse, addiction, and the opioid crisis,’’ the White House said in a statement.

‘‘I made a promise to the American people to take action to keep drugs from pouring into our country and to help those who have been so badly affected by them,’’ Trump said.

A Post investigation revealed that the opioid epidemic erupted several years ago as the DEA slowed its enforcement.

Asked about the recent survey findings, Payne, the DEA spokesman, said the rise in heroin use and, more broadly, opioid abuse is manifested through ‘‘monster increases’’ in border seizures of heroin and other opioids, such as fentanyl, and a ‘‘huge spike’’ in internet sales of fentanyl-based compounds from China.

He said it is also seen in emergency room visits and tragic overdose deaths that have been grabbing headlines across the country.

In particular, Payne said, New Hampshire, Ohio, and West Virginia are struggling with ‘‘significant amounts of abuse and addiction.’’

Martins, the lead author of the new study, called for more intervention and education efforts to help curb not only heroin use and addiction, but also the greater opioid epidemic in the United States.

‘‘The findings show us that we truly have a heroin epidemic in the US and that we need to tackle it in better ways,’’ Martins said.