I’m on 7.5 mgs/day.  Like your situation, Michelle, it’s the prednisone that is causing my depression.  Basically about 5 years ago an old endo upped my meds to 10 mgs/day and thats pretty much when all my problems started.  My weight... Depression and all of it’s wonderful side effects... The mood swings became really bad as well...  But the new endo I’ve been seeing had reduced my meds about a year ago and I’ve lost alot of weight and felt somewhat better.  Yet I still feel down sometimes for absolutely no reason.  It’s like you said,  there’s no logic to it. 

Also I still have many of the physical effects of depression which made me think I had adult ADD instead.  Basically, my family doctor said that because of the preds I have to "reset the chemicals of your brain," as he put it.  I’m going to get a second opinion from my endo and see what he says before I take any sort of anti-depressant. 

Out of curiosity, does anyone here feel somewhat slower mentally when they take their preds?  I actually have better days with a clearer head when I forget to take my medication.  Weird, eh?  That’s something that’s been increasing with me over the years and one of the main reasons I spoke to my doctor about it. 

Anyways, Im getting a headache trying to focus on this right now soooo i’ll try to be back later in the day to post some more.  lates!