I'd be surprised if it wasn't the majority of people with anxiety/depression who hide it well (enough) externally so people don't know. I've been suffering from clinical depression since my early 20s, and not many people would guess that from talking with me...
My appendix ruptured while I was in the hospital waiting room and I *STILL* almost died. The amount of pain I was in is indescribable. The fact that he was trying to play through that is ridiculous.