Feeling dumb and sleepless from scrolling through short videos? 71 studies reveal the brain costs of TikTok.

Short video platforms such as TikTok, Reels, and YouTube Shorts have become an indispensable part of modern life. However, a systematic review and meta-analysis covering nearly 90,000 participants and a total of 71 studies shows that excessive use of short videos is moderately associated with decreased attention, impaired self-control, and other cognitive function degradation.

The influence of short videos is not limited to entertainment

Short-Form Videos (SFVs) were originally focused on entertainment, but have now widely penetrated fields such as education, political propaganda, and consumer marketing. These videos quickly capture users' attention through algorithmic recommendations and an infinite scrolling interface design, also increasing users' engagement. Research indicates that while this design enhances user participation, it has also raised concerns about “digital addiction” and mental health.

With its unique algorithm recommendation system, TikTok accurately pushes content that users love, quickly igniting a trend among the global youth. Instagram Reels cleverly integrates IG community influence, allowing creators to precisely reach existing fans, and through algorithm recommendations, expands to the “Explore” page, reaching a broader potential audience. YouTube Shorts integrates YouTube's massive user base, helping creators quickly connect with existing subscribers and expand to a whole new audience through algorithmic outreach.

The high frequency and stimulating content of short videos may have long-term effects on the brain's cognitive processing ability. This meta-analysis led by Griffith University in Australia integrates data from 71 studies involving nearly 90,000 participants, providing the most comprehensive evidence base to date for understanding the actual impact of short videos on health. Such large-scale systematic reviews are extremely rare in the field of social media research, and their conclusions are highly credible.

Heavy use is moderately associated with cognitive decline

The integrated analysis shows that there is a moderate negative correlation between the use of short videos and overall cognitive function (r = -0.34). Among these, attention (r = -0.38) and inhibitory control ability (r = -0.41) are most significantly affected. This correlation coefficient is considered “moderate strength” in social science research, indicating that the use of short videos does indeed have a measurable negative impact on cognitive function.

Research indicates that repeated exposure to fast-paced, highly stimulating short video content may lead users to experience “impatience” and “decreased attention” when engaging in slower-paced activities that require sustained focus, such as reading or problem-solving. This phenomenon is known in academia as “attention fragmentation.” After the brain becomes accustomed to short, high-stimulation information input patterns, it develops resistance to tasks that require prolonged concentration.

The decline in inhibitory control ability deserves more attention. Inhibitory control refers to the ability to suppress inappropriate behaviors, resist temptations, and control impulses, which is a core component of executive function. When inhibitory control ability declines, it becomes more difficult for individuals to control their behavior of scrolling through short videos, creating a vicious cycle: the more they scroll, the harder it is to stop, and the harder it is to stop, the more it affects cognitive function.

Three Major Negative Impacts of Short Videos on Cognitive Function

Shortened Attention Span: After getting used to content lasting 15-60 seconds, there is resistance to tasks that require prolonged focus (reading, studying).

Inhibition Control Ability Decline: Difficulty in controlling the impulse to scroll through short videos, with “just one more” turning into an endless cycle.

Decreased Deep Thinking Ability: The brain adapts to rapid switching and shallow processing, making it difficult to tackle tasks that require deep analysis.

Research further indicates that the dual effect of “habituation + sensitization” reduces the brain's tolerance for activities that require effort and delayed feedback. The instant gratification and dopamine stimulation provided by short videos make the brain impatient with the traditional reward model of “effort → delay → reward.”

Algorithm reward mechanism weakens self-control

Short video platforms enhance users' “instant gratification” through real-time feedback and dopamine stimulation. This design is similar to reinforcement learning, leading people to keep scrolling and forming habitual use. Such high-frequency stimulation not only decreases users' tolerance for long-duration tasks but may also weaken the functions of brain areas like the prefrontal cortex that are responsible for control and focus.

The core of the algorithm reward mechanism lies in “personalized recommendations.” The platform tracks every interaction of the user—time spent, completion rate, likes, shares—and continuously optimizes the recommended content based on this. This mechanism is extremely effective; the content users scroll through increasingly aligns with their preferences, leading to the phenomenon of “not being able to stop.” This is not due to the user's weak willpower, but rather an inevitable result of the algorithm design.

The infinite scrolling design of short videos eliminates natural stopping points. Traditional media (such as TV shows or movies) have clear beginnings and endings, but short video platforms adopt an Infinite Scroll design, where the next video plays automatically without any stopping cues. This design deliberately circumvents users' rational decision-making, making “watching one more” an automated behavior.

Mental health raises red flags, anxiety and stress are most affected

In 61 studies examining the relationship between short videos and mental health, the overall results indicate a slight to moderate negative correlation between the two (r = -0.21). Particularly, anxiety (r = -0.33) and stress (r = -0.34) showed the most significant effects, while depressive symptoms and feelings of loneliness also exhibited weak negative correlations.

Moreover, if the time spent using short video platforms is concentrated before bedtime, it may disrupt the secretion of melatonin, affect sleep quality, and further weaken psychological regulation abilities. Blue light exposure is one factor, but more importantly, it is the stimulating nature of the content. The fast pace and emotional fluctuations of short videos keep the brain in an excited state, making it difficult to enter a relaxed and sleep-ready mode.

Surprisingly, the use of short videos is not significantly related to self-esteem or body image. Researchers speculate that this may be related to the increase in diverse and positive body image content on the platform, in contrast to past social media that emphasized appearance comparisons. Future research should further differentiate between different types of content to clarify these inconsistent results.

Age is not a determining factor; both teenagers and adults are affected

It is worth noting that research has found that age does not have a significant moderating effect on the relationship between short video usage and health. In other words, whether teenagers or adults, excessive use of short videos can lead to similar negative effects. This slightly differs from the common belief that teenagers are more easily influenced by social media, and it also shows that the “universal appeal” of short video platforms may have effects across age groups.

Further research found that the measurement indicators of “short video addiction” have the strongest correlation with psychological and cognitive health, while studies that assess based solely on duration or frequency of use show a relatively weaker correlation. This indicates that addiction tendencies (such as loss of control and inability to stop using) are more reflective of potential health risks than mere usage time. Furthermore, “general platform users” (those who use multiple short video platforms) exhibit a stronger negative correlation than users who only use TikTok, suggesting that cumulative use across multiple platforms may exacerbate health impacts.