A person only knows their own experience. Everyone thinks they know depression as everyone has been sad and has grieved. How do they know that someone else's moods might not cover a greater spectrum than theirs? People don't like that thought as it sounds self-indulgent (my pain is worse than yours it sounds to them) but in the same way that some people's kidneys might not function quite as well as the average person then it makes sense that there would be people whose brains - which is after all a far more complex organ - might not operate (by the measure of mood) to the average level. I thought I saw something recently on BBC or somewhere about brain-imaging bipolar patients and how the hypocampus (if it's spelt like that) was markedly different in bipolar people? I do think there's something chemical or physical going on personally. I'm no neurologist myself but I think as that science advances they will uncover more evidence. After all, it was only a matter of decades ago when mental illness became formerly recognised beyond the terms lunatic yet I assume (I'm no history buff either) that you could go back through history and find cases of mental illness. Less than today but still present.

I struggle with this too as there's no doubt I create a lot of my own problems but there's something going on. What's my doing, what's symptomatic of illness, what's caused by events around me, how do those experiences differ to the average person?

Ultimately it makes no difference when you are in the eye of the storm. You just need to do and believe whatever is necessary to get through it. Let the moral judges make their judgements about good and bad, strong and weak, and whatever else from their ivory towers if it makes them feel better. For anyone else seriously afflicted you just have to manage as well as possible by any means necessary. There will be times when you can cope and times you need help. Extra guilt piled on top for suffering from the problem doesn't help but I bet we all do it. I know I do.