I have found I have been making some serious mistakes at my job resulting from depression, anxiety and stress. Now I'm in a position that I need to my boss before she decides that I can't do my job. I have to say, I'm very anxious about her response. I did speak with her quite some time ago on some other issues and her response was to "stay positive" in other words I felt like she was telling me to "shake it off" I don't expect any sympathy, just some understanding that sometimes we are "not well" and need a little help. In my opinion depression is no different than other illnesses it's just that you can't see it.
I agree with AnneMaryCR not to give 'too much information.' I believe this is one case where less is better.