My big issue with this study is it points to a cause. How can they know the issue is social media, and not, say, the climbing atmospheric CO2 or other long-COVID related issues?
The root cause is likely to the surge of dopamine in the brain related to activities like scrolling social media, fast-paced tik-tok videos, porn, etc. This means that the brain is so much addicted to this dopamine that normal level are no longer enough to be functional.
There can be many causes. Aside from social media, games, porn and AI, it can also be caused by the decline of the living standards or increase of stress in the West due to shift from social-democratic to neoliberal economic policies.