The CDC put out an 89-page summary of trends from its Youth Risk Behavior Study (YRBS) data from 2011 through 2021, and, Jon Haidt reports, there’s not much evidence of a covid effect:
If we start with girls, we see a steady rise since 2011, with an acceleration in the 2019 administration, and then, if you squint, you can see a slight acceleration beyond that in the 2021 administration. We can call that extra acceleration the covid effect. For the boys, we see no covid effect at all. The big jump was between 2017 and 2019, and the rise slows down between 2019 and 2021.
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Why did covid not cause a bigger increase in teen mental illness?
My tentative answer: When school closures and social distancing were implemented in 2020, teens had already lost most of their social lives to their phones. You can see the spectacular loss of time with friends in this graph of time use data plotted by age group.
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So 2 hours a day with friends was the norm right up to the time when teens traded in their flip phones for smartphones, in the early 2010s. Once they did that, they moved their social lives onto a few large social media platforms, especially Instagram, Snapchat, and later Tiktok. They were spending vastly more time online, even when they were in the same room as their friends, which meant that they had far less time for each other (in face-to-face interaction or physical play).
I suggest that this is why the effect of covid restrictions on teen mental health was not very large: Gen Z’s in-person social lives were decimated by technology in the 2010s. They were already socially distanced when Covid arrived.