Earlier quoted context omitted.
Thanks for the perspective, and ditto. It sounds condescending, and obviously physical brain damage (e.g. CTE) can cause depression completely separately from life circumstances, but I would venture that for a majority of people who say "My life is just fine but I am depressed anyway", their life is not actually fine. It's not even that they are lying, but we humans are very good at hiding truths, even from ourselves…
But drugs are awesome :D Seriously though, compared to being depressed when you can't fix it because you don't have any idea that something is wrong, drugs are fucking amazing. The shitty part is people end up trapped now as the drugs can fuel the negativity which lead to the depression in the first place.
The common thread though is that a single dose of the drug offers long-lasting protection, weeks or months or years. It's not about chemically changing the brain day after day, it's about using neurochemicals to jolt the brain out of a rut. It's about occasionally kickstarting the brain back into normal self-regulation, not using externally supplied chemicals to permanently supplement dysregulation.