Boomers had one of the greatest economic runs in history during their teen years.
Generation X was subject (if they had blue collar parents) to offshoring of jobs from the United States in their teens.
Millennials were mostly the product of white collar workers who chose to have children later and thus were financially better adapted to the new economy in their teen years.
Generation Z is having to contend with the shaky economic conditions and deregulation since the last recession while having to deal with what's essentially a fourth industrial revolution (social media, AI; photography, music, and art related professions becoming obsolete, etc.)
I would also say that the teen years are always the hardest and most difficult years in one's life, especially since you feel like an adult but aren't, want to do things but can't, and are subject to the economic whims of ones parents yet feel like one needs material things in order to socially fit in and relate with one's age group especially those who have parents who are far better off then yours. This creates over time a sort of natural segregation where as one moves into adulthood you tend to settle down and only relate/have friends with those of your own socioeconomic class, but as a teen you're forced to only be with those of your hometown or more specifically your school. So if you come from blue-collar stock but in a town that's demographically changing and becoming increasingly white collar it can be rough. I imagine with adulthood and thus personal mobility social anxiety and thus suicidal thoughts decrease as one can move to a workplace/town that has one's "own kind of people" from which to fit in and become part of a tribe.
The recent increase of girls commiting suicide at all time highs is probably because of the fear of creative professions being eliminated as females tend to be more artistically inclined. Social media is likely designed to mess with the female brain more than men because as you should know social media sites like Facebook were invented by Zuckerberg to rate women in college and pressure them into having sex with the tech bois.