That's scary: "Tik Tok Brain"

A 2021 study on TikTok’s specific neurological effects examined how Douyin, China’s TikTok equivalent, affects Chinese college students’ brains.3 It found that watching personalized, algorithm-selected videos activates reward centers in the brain much more than watching random videos that haven’t been chosen specifically for the viewer. Brain scans of students who used the app regularly revealed addiction-like responses, and some research subjects lacked enough self-control to stop watching.

“If you are watching TikTok for long periods of time, it may lead to problems with attention, concentration, and short-term memory.” Griffin said.

In addition to the specific impacts of viewing short-form, personalized videos on a consistent basis, TikTok also presents the same challenges for young people as all other social media platforms, according to Griffin.
This includes a reduction in real-life interactions that can lead to stunted emotional and social development, as well as the possibility that even with parental controls, children will be exposed to potentially upsetting, harmful, or inaccurate information.