Introduction
Meta has agreed to pay up to $18 billion to settle claims from U.S. States alleging that Facebook and Instagram misrepresented the risks their platforms posed to children’s and teenagers’ mental health. With the proposed agreement including changes to platform features, such as daily usage limits, restrictions on nighttime notifications and options to disable autoplay and personalised feeds, these developments form part of a wider international debate about the potential harms of social media use among young people and the measures needed to protect their health and wellbeing.
To better understand how social media may affect young people and whether the risks stem from the amount of time spent online, the content they encounter or a combination of both, we reviewed 17 studies involving more than 5,000 participants, mostly young adults.
We explored how patterns of social media use - including what people watch, why they start scrolling and whether they feel able to stop - may influence attention, memory and mental health.
Concerted attention and self-control
Across the studies, the clearest pattern concerned attention and self-control. People who used short-form video heavily - or felt unable to control their use - more often reported losing focus, struggling to redirect their attention and acting impulsively.
In experiments, some participants focussed on images for shorter periods, moved their gaze more often or found it harder to ignore distractions. A small number of studies also found differences in brain activity linked with control and reward. However, these results were inconsistent and heavier users sometimes performed just as well as other participants on attention tasks.
Impact on memory and mental health
Only two studies examined memory, but both raised concerns. One associated heavier social media use to difficulties remembering things people intended to do later, while another found that participants remembered less when they used Instagram while learning. Anxiety was more often linked to using short-form videos to escape difficult feelings or struggling to stop watching, while depression showed no consistent link with social media use.
But the findings weren’t all negative. In some laboratory experiments, watching short, positive videos could lift people’s mood. Taken together, the results suggest that it’s not only a question of how much time young people spend on social media. What they watch, why they turn to it and how much control they feel they have over their use may all play a part.
What we still do not know
Our reviews do not show that short-form video causes lasting damage to young adults’ brains. Most studies captured a snapshot of people’s social media use and wellbeing at a single point in time, often relying on participants to report their own habits and difficulties. While this can reveal links between the two, it cannot tell us which came first.
Young adults who already feel anxious or struggle to focus may be more likely to use short-form video heavily. Equally, heavy use could contribute to these difficulties or the two may reinforce each other. A small number of studies found differences in brain activity among people with heavier or more problematic use; however, these findings do not prove the brain has been damaged, nor do they show that short-form video use was responsible.
Why people scroll
The same amount of screen time can create very different experiences. Consider two people who each spend an hour on TikTok or reels, for example - one chooses cooking tutorials, shares a few clips with friends and then closes the app. The other opens it when feeling stressed, starts endlessly scrolling and finds it difficult to stop.
Even when people spend the same amount of time online, their reasons for using social media, their behaviour and their sense of control can differ. Studies in our review linked boredom, difficulty managing emotions and using videos to escape with more problematic patterns of use, suggesting that why people turn to social media is just as important as how long they spend on it.
How platform design influences use
Platforms such as TikTok, Instagram and YouTube continuously serve up short videos and reels selected to match each user’s interests. Because these videos play automatically and there is always another one to watch, it can be easy to keep scrolling for longer than intended and potentially influence how people use these platforms and how easy they find it to stop.
Recent policy developments, including the Meta settlement in the US, reflect growing concern about how social media platforms are designed to keep people watching. In the UK, where the government has announced plans to restrict under-16s’ access to social media, we submitted evidence from our review to Parliament’s inquiry into children and young people’s mental health, while other research found support among young people for action to restrict platform features that encourage prolonged use.
What should happen next?
Schools should support young people understand how features such as personalised feeds, autoplay and endless scrolling can encourage them to keep watching and how to recognise when they want to stop.
Healthcare professionals should also consider not only how much time young people spend online, but whether their use affects their sleep, mood or self-esteem or exposes them to distressing content. Researchers also need access to actual usage data, rather than relying on people’s estimates of their screen time.
We are preparing our findings for publication, with a quantitative study planned next. By bringing the results together with our review, we aim to develop a framework for understanding how patterns of social media use and platform design may be linked to both benefits and difficulties.
Screen time alone cannot provide us with a complete picture of how social media affects young people. We also need to understand what they watch, why they keep watching and whether they feel in control of when they stop.
