TikTok offers community to people with mental illness, but a University of Minnesota study found that the popular social media app can be a "runaway train" of distressing videos because of how it picks content.

Detailed interviews of 16 TikTok users confirmed the suspicions of U computer scientists: The app's algorithm can draw people together around videos they find interesting, fostering community, but it can do damage if it force-feeds content that triggers anxiety.

"Users are along for the algorithmic ride with little ability to affect what the train is doing," they reported. "The train takes them to places they may not ... want to be ... yet they cannot stop seeing it without a complete cessation of app use."

The U authors said the small study was a first step toward broader research, including solutions that make social media platforms more sensitive to mental health issues and to people who need breaks from mental health content. The study will be featured next week at a conference in Germany on human-computer interaction.

TikTok is often minimized as a source of dance and comedy videos, study coauthor Stevie Chancellor said, but it has become a relevant gathering place for mental health support and information. A review of 100 videos with mental health hashtags showed they had been viewed 1.3 billion times.

People explore TikTok for clinical information, but sometimes they just want practical tips from others dealing with the same kinds of stress, or a video of kittens to brighten their day, she added. Informal support communities grow around popular videos and content.

"I don't want to throw TikTok out with the bathwater, because it does provide this really useful forum for disseminating mental health information and sharing personal experiences," she said. The U assistant professor specializes in artificial intelligence to identify people in online communities at risk for severe health problems or behaviors.

TikTok's algorithm brings relevant videos from across its platform to people based on their apparent interests. Facebook focuses more on content based on friends and followers, Chancellor said.

The findings about TikTok rang true with clinicians, who discuss with patients how to maximize the benefits of social media while minimizing harms.

"When we think about mental health, one of the things people seek out the most is not feeling alone and feeling understood," said Sarah Jerstad, clinical director of psychological services for Children's Minnesota. "This is a way for people to put out their own experiences in small bites about mental health struggles and to get support."

Jerstad advises patients to discuss what resonates with them on TikTok with health care providers, rather than trying to self-diagnose.

"It's great to bring that to a therapist or a primary care doctor or a caring adult in their life and to be able to say, 'I saw this. I really relate to this. Sometimes I wonder if I struggle with this,'" she said.

Chancellor said the study was small because each interview took an hour or two, but common themes quickly emerged. The interviewees ranged in age from 16 to 54 and from working adults with spouses to single teenage students.

All valued TikTok, but they also said the app "is very sticky about content that it believes you like," even if they press a button asking to see something else, Chancellor said.

Chancellor said she wants to develop AI technology that helps social media platforms identify when people need content changes. One idea, she said, is to create a "choose your own adventure" option that offers users a choice on the genre of content they want to see.