You're absolutely right that we can be sneaky. A huge part of that is the stigma associated with depression. I'm certain that if all of my clients knew about it, I'd lose some of them for the simple fact that they'd consider me unreliable in the long term.
So, when Taren mentioned that she'd been "reading up" on depression, and concluded that that wasn't what Aaron was suffering from, I did cringe a little. I came to the comments here expecting to find some discussion of depression; what I didn't expect was the top comment completely dismissing Aaron's suicide as being only about depression.
Depression is probably different for different people, like most things. Mine simply makes me more susceptible to struggling when life gets hard. I'm rarely depressed when the sun is shining and there's money in the bank account and my car is working and my business is good and my friends and family are happy. When too many of those things are off, I feel it intensely and my default biochemical response is to crawl into a hole and want to disappear. I have to fight my way back out of that, every time.
So I find Aaron's case very easy to empathize with. If I were in his situation -- inasmuch as I understand his situation at this point -- I'm honestly not sure what I would do. I can tell you that I'd feel overpowered, hopeless, and defeated. I can also tell you that I would want to punch anyone in the face who said that if I chose to commit suicide as a result of the situation, it would be primarily because of my depression.