My best friend in college didn't know until I told her, not about my eating disorder and not about (my then diagnosed) depression & anxiety.

She said she did wonder about my weight since I was so thin in so many pictures, but I always ate normally around her. We didn't live together, and she did not realize I spent the bulk of my week overexercising and restricting to make up for spending Friday night or Saturday with her. She never wanted to come right out and ask.

Since I was baring it all, I told her about the depression & anxiety too. It seemed to throw her.

Several years ago, she visited when my daughter was in pre-school and was very shaken up. One of her good friends in vet school (and a good vet too) had suddenly given her dogs away to people who would care for them and committed suicide. My friend told me no one in her circle of her vet school class of friends could believe it.

Sometimes, I think people don't see it because they don't want to. And other times, I think they don't see it because we don't let it out and pretend like everything is normal.