Scrolling for answers

Carter Weisensel is a very active 15-year-old. He's a three-sport athlete at his high school in Stoughton, Wisconsin, and he loves to fish and race motocross.

But when he needs to relax, he sometimes jumps onto social media, where a few minutes can quickly turn into an hour - or three.

"Scrolling can give you this cheap dopamine hit," he says.

Carter is mostly an online consumer; he doesn't create a lot of content himself. When he does, it's usually related to one of his hobbies, like a recent Instagram post about the large muskie he pulled from the Wisconsin River near Sauk City.

"When you post something impressive like that, it makes you feel good about yourself," he says.

For the past two years, Carter has been sharing his online life with not only his followers but also researchers at the University of Wisconsin-Madison. He's part of a long-term, federally-funded project designed to study how social media affects the physical and mental health of adolescents, including their brain development. Carter is one of 325 Wisconsin teens ages 13-15 already recruited for the study, with a goal of 400.

Participants agree to allow researchers to closely track their online activity for two years - what they post, who they follow, the content they like and share. They also complete multiple surveys, sit for interviews and, in some cases, undergo brain scans. It's the largest endeavor of its kind, funded by a five-year, $7.5 million grant from the National Institutes of Health (NIH), the primary arm of the federal government responsible for biomedical and health research.

"Families routinely tell us that social media is a significant and almost unavoidable part of teen life these days," says Dr. Megan Moreno, a pediatrician and the study's lead researcher. "There is an urgent need to better understand both its risks and its benefits."

A critical part of the work is to bring findings back to Wisconsin communities and share them with youth, families, healthcare providers, educators and policymakers, says Moreno, a professor and the vice chair of academic affairs for the Department of Pediatrics at the University of Wisconsin School of Medicine and Public Health (SMPH).

Prior research has tended to be fragmented and narrow in scope, with the lens often focused on risks, she says.

"Our study is broad and doesn't have a negative or a positive slant," Moreno says. "We're not trying to say that social media leads to a lot of bad things or that it is going to save the world. It's an inquiry study, and I think that's one of its major strengths. We're just really curious."

Social media can help adolescents make friends, share information, and develop aspirational identities for who they want to be offline, Moreno says. It also can deliver novel interventions for teens who need mental health support, she says. At the same time, previous studies also have shown that social media use among adolescents can impair sleep, decrease physical activity, and increase the risk for depression and other negative outcomes.

Three studies in one

The UW-Madison research project encompasses three independent studies, each led by a different researcher and covering a distinct area: behavior, well-being and the brain. All three studies draw from the same participant pool.

Moreno's study is focused on behavior. It seeks to understand more about how social media influences everything from the amount of physical activity and sleep a teen gets to the likelihood the teen will engage in risky behaviors like consuming alcohol or taking drugs.

The well-being study evaluates whether engagement with online content - both self-generated and created by others - can predict an adolescent's social and emotional health. The study looks at concepts like self-esteem, loneliness, stress and emotional difficulties, all of which contribute to the overall mental health of an adolescent, says Dr. Ellen Selkie, who leads this portion of the study. She is a pediatrician and an assistant professor in the Department of Pediatrics at SMPH.

The final study area, led by Associate Professor Chris Cascio of the UW-Madison School of Journalism and Mass Communication, uses magnetic resonance imaging (MRI) to understand how adolescents process positive and negative social media experiences and how those experiences affect their mental health and health behaviors. This part of the project relies on a subset of participants who agree to undergo brain scans while being presented with hypothetical social media scenarios and tasks.

"We want to understand who is thriving online and who is susceptible to harm," says Cascio, who directs the Communication, Brain and Behavior Lab within the university's Mass Communication Research Center. "Two adolescents might see the same information and respond differently. One might be resilient; the other might become depressed. By studying the underlying brain mechanisms, we can figure out how best to intervene."

Aligns with bipartisan priorities

The NIH awarded UW-Madison the competitive grant in 2022 and Moreno says the study's goals continue to align strongly with the current administration's Make America Healthy Again agenda. U.S. Health and Human Services Director Robert F. Kennedy, Jr. has publicly voiced concern about the impacts of social media on adolescent mental health and academic performance.

Still, the Trump administration froze funding for the grant in March of 2025 as part of a wave of cuts to research programs at universities across the country. The termination notice that Moreno and her research team received said that the grant no longer "effectuates agency priorities," and that "it is the policy of the NIH not to prioritize" research programs that are "based on gender identity." A small piece of Selkie's study is designed to compare whether adolescents from sexual and gender minority groups experience social media differently from their majority group peers.

UW-Madison appealed the funding freeze and joined other universities in a lawsuit seeking to restore federal research dollars. As part of the appeal, the UW-Madison researchers offered to remove the comparison portion of Selkie's study involving minority groups so that the remainder of the project could proceed. (Selkie is seeking funding from non-federal entities to conduct this part of the research.)

The funding for the UW-Madison study has recently been restored, driving Moreno and her colleagues to jumpstart recruitment of more adolescents - work that has been challenging given the loss of some staff during the termination. Those working on the study have been told the funding may or may not be at risk for another termination going forward. Full termination of the grant would be devastating, the researchers say, negatively affecting their study teams and the adolescents and families who've committed so much time and energy to the effort. It also would squander taxpayer money already spent on the study while delaying and jeopardizing crucial findings. Even the delay already caused by the six-month funding freeze has led to an extension of the study's end date. Termination in a longitudinal study would mean that some participants don't go through all the steps, leading to data that can't be used and analyses that can't be conducted.

"If you asked any parent out there, 'Do you care how social media affects the health and well-being of your child?,' I think most parents would say, 'Of course I do,'" Cascio says. "I'm passionate about this work because it's research I really care about. But I'm also the dad of a 6-year-old daughter. I'm concerned about the influence of social media and what she'll come across. As a parent, I want to know how to guide her."

Amanda Weisensel, Carter's mom, says she was glad to see the government putting significant money into social media research.

"I'm worried about my children and other children," she says. "My main concerns are the bullying and the people who are predators. It's so easy to disguise yourself as something else on the internet these days. Especially during tense political times, all the information kids receive is pretty much from social media, and the truth behind all of that can be not what you think. How it influences our kids is a big concern."

Opportunities for UW students

The work performed as part of the project so far has benefitted UW-Madison students and early-career scientists, as well as the local economy. It has supported 10 staff members, 40 student workers, and two post-doctoral researchers. For the students assisting in the work, the study has provided them with valuable, real-world research experience.

"I wanted to fully immerse myself in a research opportunity during my time at UW, and this one really caught my eye because it's so relatable," says Lily Stratman, a junior biology major from Marshfield, Wisconsin.

In her work as a student intern with the study, Stratman spends an average of five to six hours a week tracking the social media activity of participants and coding what she finds based on a multitude of categories and factors. This coding, coupled with survey and interview responses, may help researchers determine to what degree online activity predicts offline behavior.

"If a teenager lip-synchs to a song on TikTok about drinking or doing drugs, does that mean they're participating in those behaviors offline, or does it simply mean that it's a popular song and they're just trying to keep up with their friends?," says Abby Hommer, of suburban Chicago, who worked on the study for several years as a UW undergraduate. She's now pursuing a master's degree in mental health counseling at Marquette University and believes her work on the study will be invaluable to her future goal of counseling adolescents.

Teens recruited from across Wisconsin

As part of their work, UW student interns have helped recruit participants across the state, explaining the research at county fairs, school events, community gatherings and the Wisconsin State Fair.

Denyah Tinnon heard about the study at a community event in Green Bay, where she's a high school junior and a member of the National Honor Society. She plays volleyball, competes in track and field, and participates in the Future Business Leaders of America club.

In the summer, when her life is slower, she spends about 90 minutes a day on social media. She's a regular on TikTok, Snapchat and Instagram but not Facebook. ("Not to be rude, but that's for old people," she confides.)

Left: High school junior Denyah Tinnon, at her home in Green Bay, is one of 325 Wisconsin teens recruited for the long-term research project at UW-Madison. Right: Tinnon offers a glimpse into her social media activity with a sample of her "outfit-of-the-day" posts.

Asked what appealed to her about participating in the study, Denyah replies, "Can I be real? It was the money." It's not an uncommon response. Participants could earn at least $300 and up to $420 if they undergo MRIs. Offering compensation to research study participants is common practice to help scientists ensure they have the participant pool they need to draw meaningful and reliable results.

Denyah says she posts four or five times a week on social media, often sharing her "Outfit of the Day" with her followers. She views social media as mostly a positive in her life and in society in general.

"You can express yourself and find people who are like you," she says. "And you can even get famous."

She has occasionally glimpsed the downside.

"You can get bullied on there or talked about negatively," she says. "One person who didn't like me said something bad about me, but I just blocked them. I'm not going to let someone talk about me like that on my own device."

Denyah says she was also drawn to the study because it's being conducted at UW-Madison, an institution she might want to attend one day.

"Research is so important, and I think it's really cool that they're collecting data from teens," she says. "When they do publish the results, I'll be able to say, 'I was part of that.'"

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