Whether it's fears over Chinese espionage or complaints over suicide themed content, TikTok has made plenty of negative headlines in recent years.
The social media platform which lets users endlessly swipe through videos tailored to them via a highly effective algorithm has exploded in popularity and is believed to have over 1 billion users.
While it gained a reputation for viral dances and entertaining trends to keep people occupied during COVID-19 lockdowns, the app has increasingly been accused of negatively impact people's mental health.
It's also being seen as a security risk, with parliament recently banning the Chinese-owned app on local networks and staff devices over concerns it could be used to pass intel to Beijing. The US are even considering a complete ban.
Plenty of people who've used TikTok will tell you how addictive they find it, something which is now being confirmed by studies.
It is now feared that the compulsion to keep watching an endless supply of 20-second videos could be impacting our attention spans, although the exact impact remains unclear.
"A lot of my friends at university have TikTok and they’re not really getting their work done, they’re getting very distracted," a law student told LBC's David Lammy on Sunday.
She added: “I felt it myself when I had the app. You’re getting extremely overstimulated and you’ve got an extremely short attention span and it’s impacting your everyday work.”
How much is TikTok affecting our attention spans?
Given the relatively recent rise of TikTok, many claims of dwindling attention spans are anecdotal, but preliminary research is also pointing in the same direction.
A study by China’s Zhejiang University showed that when shown personalised videos on Douyin, China’s version of TikTok, areas of the brain associated with addiction were highly activated in students, some of whom struggled to stop watching.
“We speculate that individuals with lower self-control ability have more difficulty shifting attention away from favourite video stimulation,” researchers wrote.
Many scientists believe that watching such short and fast paced videos on a regular basis will make it harder to focus on things that don't offer the same instant gratification, particularly for children.
Carrying out a task that requires prolonged focus, like reading a book or solving a puzzle, relies on the prefrontal cortex.
This part of the brain is responsible for decision making and impulse control, and isn't fully developed until around age 25 - meaning children can have more trouble focusing.
Sustained attention isn't required for TikTok's constant stream of short clips, which might explain the app's appeal, although it has recently enabled users to upload longer videos.
Dr Carl Marci, a psychiatrist at Massachusetts General Hospital, told the Wall Street Journal: “In the short-form snackable world, you’re getting quick hit after quick hit, and as soon as it’s over, you have to make a choice."
Being exposed to this kind of content too frequently could make it harder to adapt to the outside world, explained Dr Michael Manos, of Cleveland Clinic Children’s Center for Attention.
“If kids’ brains become accustomed to constant changes, the brain finds it difficult to adapt to a non-digital activity where things don’t move quite as fast,” he said.
Is only TikTok to blame?
While TikTok takes much of the flak for this perceived decline in attention spans, some studies suggest it's a bit more complicated than that.
A 2019 study published in the Nature Communications journal found that our collective attention span is narrowing.
Researchers at the Technical University of Denmark looked through Twitter data from 2013 to 2016, books from Google Books going back 100 years, data from Google Trends, Reddit and Wikipedia stretching back to 2010.
This goes back before the meteoric rise of TikTok, but scientists still found a significant drop in attention spans over time.
For example, when looking at Twitter's global daily top 50 hashtags, researchers found that in 2013, a hashtag stayed in the top 50 for an average of 17.5 hours, decreasing to 11.9 hours in 2016.
Similar trends were observed in Google searches and the number of Reddit comments on individual submissions.
This suggest that while TikTok may be a piece of the puzzle, the issue could be much more broadly about our ever-growing appetites for new and engaging content.
The researchers add: "Acceleration increases, for example, the pressure on journalists' ability to keep up with an ever-changing news landscape.
"We hope that more research in this direction will inform the way we design new communication systems, such that information quality does not suffer even when new topics appear at increasing rates."