I did a quick google and found > The total number of teenagers who recently experienced depression increased 59% between 2007 and 2017. The rate of growth was

I did a quick google and found > The total number of teenagers who recently experienced depression increased 59% between 2007 and 2017. The rate of growth was faster for teen girls (66%) than for boys (44%). (https://www.pewresearch.org/fact-tank/2019/07/12/a-growing-number-of-american-teenagers-particularly-girls-are-facing-depression/ https://www.pewresearch.org/fact-tank/2019/07/12/a-growing-n...) So that's some evidence that we really are getting less happy. I would say the biggest change over that time period is smart phones became ubiquitous.