Heavy short-form video use is linked to weaker focus and less activity in the part of the brain that handles self-control. A huge review of 71 studies and 98,299 people found that the more time someone spends on TikTok, Reels, and Shorts, the worse their attention and self-control tend to be. Attention and self-control, meaning the ability to stop yourself from doing something on impulse, showed the strongest links in the review, which Psychological Bulletin published in 2025. Stress and anxiety were linked too. The pattern showed up in teenagers and adults, on every app studied. Forty-eight young adults wore brain sensors during an attention test in a 2024 study in Frontiers in Human Neuroscience. The ones who said they struggled to stop watching short videos showed weaker brain-wave activity at the front of the brain, the area behind your forehead that handles planning and self-control. They also rated their own self-control lower. Body image and self-esteem showed no link to short video use at all. And the link could run the other way, since people who already find it hard to focus may be drawn to 30-second clips. Across almost 100,000 people, heavy scrolling still went with weaker self-control, the exact skill you need to put the phone down.