(CNN) In May, a report by the National Academies of Sciences, Engineering and Medicine said young people were staring down a "serious public health problem." But it wasn't drugs they were worried about, or alcohol. It was bullying.
Researchers have long looked for a way to prevent bullying in American schools, but the problem persists, and no one can seem to agree on a surefire way to address it.
But Finland has piloted a program that has seen widespread success in combating bullying in schools. It's been translated and licensed to countries across Europe. But some researchers say it wouldn't work in the US.
"The United States is a different beast," said Dorothy Espelage, a psychology professor at the University of Florida who studies bullying and harassment.
The program is called KiVa -- short for "kiusaamista vastaan," which means "against bullying." The Finnish government helped fund its development and it's now being used in schools throughout the country.
It was developed by educators and researchers at the University of Turku, and multiple studies show it effectively curbs bullying by focusing on classes as a whole, instead of addressing individual bullies and their victims.
"The idea is that kids bully to gain status and power," said Julie Hubbard, a psychology professor at the University of Delaware who's studying KiVa's effectiveness with American students.
According to its website, KiVa's curriculum uses lessons and computer games to change that dynamic by focusing on bystanders who witness the bullying.
"If you can get the bystanders to focus on the victim and not the bully, then bullying isn't a very rewarding thing to do," Hubbard said. The hope is that this fosters a culture where bullying is socially unacceptable.
A 2016 study conducted by researchers at the University of California Los Angeles surveyed more than 7,000 students between the 4th through 6th grades in nearly 80 Finnish elementary schools. About half the schools received KiVa intervention while the others didn't.
Researchers found the program significantly helps victims of bullying, and data even suggested KiVa could decrease depression in the victims and raise their self-esteem.
One of the reasons KiVa wouldn't work is because it wasn't developed for an audience as diverse as the US public school system.
"Finnish students are homogeneous economically, racially and culturally," Espelage, the University of Florida professor, said, "whereas US schools are distinctly diverse on socioeconomic status, ethnicity and religious background."
According to Espelage, the social inequalities these students face -- whether it be race or class -- increase the risks of bullying.
If kids have different races and different socioeconomic backgrounds, other kids are more likely to bully them around those issues.
"Kids that are in the minority of the school tend to be victims of bullying," Espelage said.
According to the National Center of Educational Statistics, the average racial make-up of American students in 2014 was 50 percent white, 25 percent Hispanic and 16 percent African American. The remaining nine percent consisted of Asians and Pacific Islanders, Native Americans and those of mixed race.
Compare that to UCLA's study of KiVa, where all but 2.1 percent of the participants were white Finnish students.
Schools in the United States also have varying levels of funding and access to resources, and the problem is even more evident in predominantly African American and Hispanic neighborhoods where students are more likely to attend poorer schools, Espelage said.
"Education is local," she said. "There's not going to be one program that fits all. It's going to have to be tailored to the context."
Todd Little, a psychology professor at Texas Tech University, helped conduct an early study of KiVa in Finland, back in 2011. He agreed with Espelage's assessment of the program, he told CNN. "It worked in Finland but that is specific to the Finnish culture (and perhaps similar cultures)," he said in an email.
Hubbard, the University of Delaware professor who has completed her trial of KiVa in Delaware, said her data suggests the program can work, even across a variety of races and ethnicities. But the roadblocks to implementing a program like KiVa don't lie with the kids, she said. It's with the teachers.
Her study has not been published yet, but she shared the racial breakdown of her sample. The children in her study were 49 percent European American, 20 percent Hispanic American and 18 percent African American. Seven percent were of mixed race and six percent were Asian.
She and her colleagues looked at KiVa's effectiveness across the board to see if they differed by race. "Largely," she said, "the answer was no, we really did not see differences by child or race ethnicity."
She's more concerned with the differences between Finnish teachers and American teachers.
"Our data suggests that if teachers really implement KiVa it works well in the US for our children," Hubbard said. "But we had a lot more difficulty getting teachers to do it."
According to the National Institute of Justice, KiVa requires teachers to conduct 10 lessons over 20 hours -- a huge time commitment many US teachers can't justify when they are teaching to prepare their students for standardized tests.
Another big difference is the value Finnish society places on teachers, Hubbard said. The "best and brightest" become teachers, and they're placed on the same level as doctors and lawyers, she said. "They value their teachers that way and they pay their teachers that way."
Finland has one of the best school systems in the world. It requires its teachers to have master degrees and the government provides free access to all levels of education so children of varying socioeconomic backgrounds get equal opportunities, according to a 2015 report by the Paris-based Organisation for Economic and Co-operation Development.
Finnish students also face no national standardized tests, the OECD report said.
Teachers in the United States are "bombarded" with expectations, Hubbard said. "They're supposed to do drug prevention, they're supposed to do sex education, they're supposed to do so many things, and bullying prevention is just another thing that's on the list."
In Finland, schools placed high value on bullying prevention, and spent a lot of time and energy on it, she said.
For bullying prevention programs to work, school districts and administrators need to see that same value, and recognize it takes time and effort to work. "It's not a 30-minute assembly at the beginning of the school year and then you check that box," Hubbard said.
They also need to recognize the advantage bullying prevention programs have not just for the well-being of children, but their academics as well.
"There is such a push on improving academic standards and test scores for our kids," Hubbard said. "But I think that then these initiatives that have to do with sort of social and emotional learning and developing don't get as much attention."
In order to convince school administrators to see the benefit of these programs, we need to emphasize that decreasing bullying helps academic performance and test scores, Hubbard said.
Experts have long recommended moving away from zero-tolerance policies and towards evidence-based programs like KiVa.
"Remaining evidence-based is really important," Hubbard said.
Espelage agreed teachers in the US simply aren't able to implement a program like KiVa, but agrees that it addresses what she's found in her research; it's important to focus on "school climate," she said, instead of individuals.
She suggests anti-bullying advocates focus on funding research that takes into account the issues of our educational system and the diversity in our schools.
"We know these programs are good if kids can see themselves reflected in the program," she told CNN.
Both Espelage and Hubbard agreed the burden of solving the issue of bullying in US schools is on researchers and advocates.