Deaths from opioid overdoses rose in Minnesota last year, especially among younger adults, according to new data from the Centers for Disease Control and Prevention.

At least 338 people died as a result of opioid overdoses in Minnesota in 2015, up from 319 the previous year. The number of people being killed by opioid overdoses has risen steadily since 1999, although Minnesota still fares better than many hard-hit states like West Virginia and Maine.

Opioids are a family of drugs that includes both illegal heroin and popular prescription painkillers like oxycodone. Opioids create a strong physical dependence and can kill a user during an overdose by shutting down their respiratory system.

According to the Centers for Disease Control and Prevention, Minnesota continued an increase in annual overdose deaths. MPR News graphic

For the first time since at least the 1990s, the greatest number of overdose deaths occurred among people in their late 20s or early 30s rather than older people.

The type of opioid people use can vary by region, but synthetic opioids seem to have become more accessible recently, said Dana Farley, alcohol and drug prevention policy director at the Minnesota Department of Health.

Fentanyl, a synthetic opioid Joe Amon | The Denver Post/Getty Images via NPR file

That could account for some of the deaths among younger users, Farley said.

"We see that from the law enforcement information, that there's increased supplies coming in from South America and from overseas," Farley said. "These are starting to influence the kinds of opioids, the heroin, the strength, the increased potency."

The greatest number of overdose deaths last year occurred in Hennepin County, according to the CDC data, where opioids killed 101 people. Metro-area counties like Ramsey, Anoka and Dakota counties also lost dozens of people and had overdose death rates just slightly below Hennepin County.

In rural areas, what are you going to do when you have no money no jobs no nothing? ... You will get whatever the heck is available, and usually that's going to be some really raw, straight-up drugs, and you're at the mercy of the drug dealer.

But St. Louis County in northern Minnesota had the highest overdose death rate: at least two dozen people died from opioid overdoses there last year.

Maggie Kazel, program manager for Rural Aids Action Network, knows many of the people who died last year. They were clients who came into her center to get the overdose antidote naloxone or clean needles.

"It's hitting rural areas harder than it is cities. I think that's a hard concept for a lot of people to grasp because we have a historic setup in our brains of drugs equal big cities," Kazel said. "What we see in Duluth is horrible, what they see on the Iron Range is pure tragic."

Most of the people killed by opioid overdoses last year were white, but American Indians in the state died at a rate about five times as high. African-Americans also died at higher rates than whites.

Economic distress seems to be part of what's behind especially high opioid death rates in northern Minnesota, Kazel said, as people who are dependent on opioids scramble to get drugs of unpredictable purity or strength, which can cause overdose.

"In rural areas, what are you going to do when you have no money no jobs no nothing?" Kazel said. "You will get whatever the heck is available, and usually that's going to be some really raw, straight-up drugs, and you're at the mercy of the drug dealer."

The fact that St. Louis County is so large, and that people often need to go long distances to get medical treatment or help with addiction, makes the problem even worse, Kazel said. Even more beds in treatment centers would help her corner of the state.

Oxycodone pain pills John Moore | Getty Images file

The state of Minnesota is stepping up programs to combat the opioid epidemic, Farley said. The state Department of Health has been distributing naloxone, also known as Narcan, so first responders in eight regions in the state now have more access to it.

The CDC recently awarded the Minnesota health department about $585,000 to develop more comprehensive opioid overdose prevention plans in the state, including a program for better data collection and improvements to the state's prescription monitoring program.