what does depression look like when you have BPD?

i feel like its different from just "regular" depression i.e. chronic sadness, guilt, etc. is it?

How would we know the difference? ¯\_(ツ)_/¯

For me, it is not depression about or in response to something external as in loneliness, guilt or shame, rather it is depression about existence. Simply because I am alive, am conscious, aware that I exist I am depressed, and worse, I lack a sense of a self that is depressed. There is not a 'me,' and 'I' that is depressed; there is only depression, pure, black, nothing.

^ i second that.

with my depression its bbeen pretty treatment resistant. nothing takes away the suicidal thoughts and intense constant depression. its like im in a black hole

For me, it's like bipolar but without the mania or highs. The psychiatrist I saw described it as a depressed mood rather than clinical depression. I live with pretty much constant depression, but the depths of that depression change, sometimes several times in a day - it's like rapid cycling depression.

In case anyone wonders what I mean, there are lots of depressed moods - angry/destructive (mixed state kind of depression), despairing/hopeless, suicidal - active and just thinking about it, can't get out of bed and sleep all day depression, that kind of very passive but sad sort of depression, the irritable kind of can't be bothered/what's the point kind of depression. And the sometimes a bit more hopeful (feel lousy but can see a way forward) sort of depression. And that is how I live - different degrees of depression. Never knowing how I am going to feel in an hour, let alone tomorrow.

And very, very occasionally I get a good day - I do lots, feel positive, start looking forward, chatty, sociable etc. Go to bed and wake up.......depressed.

That's what BPD depression looks like to me.