Consistent with many other surveys, conservatives have always been less depressed than liberals. Over the time period studied, however, depression for all categories of 12th graders increased, led by liberal girls. But look at the timing:
Depression among liberal girls started moving up around 2012 and continued rising thereafter. Conservatives held out a little longer, but they were getting more depressed by 2015, albeit not at the same level. Were political events or economic trends especially traumatizing during that time period? I don’t think so.
I suspect that two developments during that era contributed to adolescent depression. The first is growth in social media usage. But I don’t think that, by itself, explains much.
I think what happened beginning around 2012, or shortly before then, was that the Left went bats**t crazy, fueled in considerable part by the far-left takeover of the public schools. The schools’ shift in emphasis from education to indoctrination, which was well under way by 2012, could be expected to have the most direct impact on high school students.
Did indoctrination make young people in the USSR depressed? Perhaps so. Jim Dunnigan writes:
One reason the Soviet Union dissolved in 1991 was that Russians were fed up the many of the Soviet era military “traditions.” After 1991, school history textbooks were revised to tell the truth about Russian history. While this was not shocking to most foreigners, especially Westerners, it was a surprise to older Russians but the young students accepted the new textbooks because it described a Russia similar to the one quietly discussed among the adults, especially the older ones, in their families.
When Putin took over after 2000, one of his first actions was to bring back the old history textbooks which lied about the Russian military. It was too late. While teachers could be forced to use these textbooks, many of their students knew someone who had used the more honest 1990s textbooks. Not only that, some of those old textbooks survived the Putin purge that was supposed to remove all those accurate history books from circulation. Many survived and continued to quietly circulate. This was another Soviet era tradition, where books from the west were translated into Russia and quietly circulated, often as typescripts. Putin began his career as a KGB officer and knew more about how the KGB tried to control what Russians thought and did than what Russians did to resist all this. That ignorance makes it difficult for Putin to understand the widespread Russian reluctance to participate in his Ukraine war.
Censorship comes back to bite the censors, because their echo chamber drifts away from reality.