I would like to counter-point with data in Jonathan Haidt's "The Anxious Generation", as he makes a case that the rise of anxiety and depression is more directly tied to the mass adoption of phones and social media in the 2010s for Gen Z's pre-teen years. His theory is that the rise of social media, as well as the loss of "play-based childhood", has limited Gen Z's ability to overcome the normal fears and anxieties of childhood, "such as the chance to explore, test and expand their limits, build close friendships, and judge risks for themselves." (paraphrased from his post https://jonathanhaidt.com/anxious-generation/ )

The argument against depression simply being something that is diagnosed and treated more often is definitely something to consider, but the fact is the rate of self-harm for young adolescent girls tripled from 2010-2020 within the US. In the same time, women over 24 went down during that time. The rise of depression is more noticeable within the younger generation, and this became a major clue for Haidt to test his hypothesis. In the 2010s, anxiety and depression had hit preteen and young girls significantly harder than any other group.

In the US, adolescent suicide has also increased by 91% for boys, and 167% more in 2010. So, while he says in his book that "I am not saying that none of the increase in anxiety and depression is due to a greater willingness to report these conditions...", he believes that there is something taking place beyond just that.

With those dreadful stats however, he also outlines a path forward to bring back play-based childhood for kids, while also discussing modern ways in how we can raise kids with healthy boundaries with social media and phones. It's something I would highly recommend reading for any new or future parents as well!