Your argument seems to hinge on this idea that a good life => no distress, which, if you've interacted with anyone diagnosed with a mental disorder, is obviously not true.
My life is great. If I didn't take a mood stabilizer, it'd probably still be good, but not as good. Regardless, my mood swings can negatively affect me and those around me.
If one day I reach a point where I can live without meds or therapy and reap no negative consequences, then yes, it would be fair at that point to say that I no longer had bipolar disorder.
> That person demonstrates that your problems are not caused by bipolar disorder. But the disorder is defined by you having problems, even though the problems come from somewhere else.
Bingo. My symptoms (mood swings) + my problems ARE the cause my bipolar disorder diagnosis. Until I had problems, I had no disorder.
What causes the mood swings, then? Genetics, upbringing, life experiences, diet, idk. Nobody knows for sure. It's an active area of research, but there is no one known cause. For all we know, there may be five independent and unrelated risk factors that lead to someone developing bipolar disorder.
It's like you get it, but you're still dismissing it for some reason. I'm curious what ulterior point you're trying to make.
Which makes the idea of "bipolar disorder" meaningless. That person demonstrates that your problems are not caused by bipolar disorder. But the disorder is defined by you having problems, even though the problems come from somewhere else.