> The madness of depression is, generally speaking, the antithesis of violence. It is a storm indeed, but a storm of murk. Soon evident are the slowed-down responses, near paralysis, psychic energy throttled back close to zero. Ultimately, the body is affected and feels sapped, drained. > > William Styron Are American's becoming more depressed? To be more specific, has the prevalence of major depressive disorder increased over the past few decades? It's typical to hear the answer: yes. There are a number of related and interesting questions here: * What predictions can we make about the growth of mental health expenditure? * Are Americas over-diagnosed for mental health disorders? * Are do mental health disorders have still have too much stigma surrounding them? * Are humans able to adapt to happily adapt to modern life? Or would were we better off as hunter-gathers on the savannah?[1] Looking at depression trends is relevant to each. But before getting too distracted, here's a simple question to start with: did the prevalence of major depressive disorder in America rise or fall from the 90s to early 2000s? One simple way to answer questions of this form is to look at a snapshot of survey responses and compare generations. If you did that and you read the following: > Members of Generation Z, born between the mid-1990s and the early 2000s, had an overall loneliness score of 48.3. Millennials, just a little bit older, scored 45.3. By comparison, baby boomers scored 42.4. The Greatest Generation, people ages 72 and above, had a score of 38.6 on the loneliness scale.[2] Then you'd conclude that Americans are becoming more lonely. This would be a mistake. Someone's loneliness may change throughout their life. Being a teenager may just be a lonely affair. What one wants to do is measure a population across time, not at a snapshot. Ideally, you'd give a representative part of the population the same survey across time. Unfortunately, that's rather elusive. Th