From my own experience and that of friends/family, when you really dig deeply you'll find that there is actually a reason for depression most of the time. The question to ask is: is this really what I want to be doing with my life right now? You may be making great money as a stockbroker on Wall Street with a great family, or earning $200k at google, but if that's not really what you want to do deep down, you may get depressed.

>I've had very large problems, and maintained mental health throughout.

There are a lot of factors that determine whether life shit causes depression.

>But that hardly means things like bacteria aren't a factor as well.

Agreed, but there isn't much evidence of that at the moment.

What if what you really want to do is lay on the couch and read or watch TV all days?

Except for some days, where you feel better, and want to be more active, and you get shit done?

And then you wish more of the former days were like the latter days, but don't understand why they aren't?

That, or if you don't have any clue what you might do differently that would make any difference at all.

>Agreed, but there isn't much evidence of that at the moment.

I haven't actually evaluated the state of the evidence. I was mainly writing to say the comment I was replying to had made a fallacy.