Here's the thing: You see obituaries which cite a "heroic battle with cancer" with some regularity. What you don't often see is a description of someone losing a heroic battle with depression. I don't know why that is. Untreated depression kills. Treated depression can still kill, and fighting it is heroic, because it's a battle every day just to remain functional.
I lost another friend to depression and I can tell you with absolute certainty that her struggle was every bit as difficult as that of anyone else afflicted with a chronic and potentially terminal disease. She didn't take the easy way out; she managed to beat the damned thing for decades.