We don't often hear questions like this asked. And I don't know many people who nonchalantly bring up these types of emotions during a friendly conversation. It's no wonder so many people go undiagnosed, and wind up suffering alone.
Is this because of stubbornness? Acceptance? Pride? Fear? Yes, yes, yes, and probably, yes. Should close friends or relatives feel badly because they were unaware? Absolutely not. I had a few caring (and present and kind) friends, after reading Us Too, tell me they wished they had known, and had done something to help me through the tough times. I am so very fortunate, but remember it was me, who didn't open up to them. For whatever reason, I kept it in. On purpose. I think many people do this.
I'm not sure it's even a conscious decision. It's not as if one morning you wake up and think: Oh shit. I know I've been feeling crappy lately, but today is different. Yep. today I should reach out to my loved ones. It's more like: Oh shit, I can't do any of this today. But again, I'm going to get out of bed and go through the motions, because I have no choice. This really doesn't qualify as a good conversation starter.
I feel like I lost my theme somewhere... Basically, until a person is ready to let you in, they may be difficult to reach or help. I think the best thing you can do, is continue being present and being kind. 🙂