I'm learning to distinguish between being depressed and being unhappy. The former is an overwhelming and global condition that colors all of my thought processes and emotions (emotional responses as well as current emotional state). The latter, on the other hand, is more akin to a current status - it's the result I get when I ask myself 'how do you feel?'
They're very tightly connected in some ways. For example, when I'm depressed, I will always answer that question with 'unhappy' regardless of what's going on in my life and regardless of 'external' conditions. However, I'm learning that it's possible to be 'unhappy' without being 'depressed' - because so long as I can prevent myself from asking that question, I don't have to hear the answer.
I know, that doesn't make much sense. Let me try again.
When I am unhappy but not depressed, there are periods of time where I am not actively thinking about how miserable I am but am in fact just 'doing stuff.' Working, interacting, doing projects, doing tasks, etc. etc. Those activities aren't really affected by the fact that I'm unhappy. The only time being unhappy comes into it is when I ask myself "are you happy?" or "how do you feel?" THEN, the answer is "unhappy." However, I can function for long periods of time and/or high percentages of the day without thinking about whether I'm happy or not.
When I'm depressed, that doesn't work. I have extreme difficulty doing anything, because I can't disengage the part of me that's concerned with how I feel. It's just too overriding. The 'feeling bad' or 'misery' overrides any other activity I undertake, and only by really heroic exertions of willpower can I force myself to function. It's like walking with a 400-lb sack over my shoulders. Whereas if I'm unhappy, it's more like walking with loose shoes - so long as I don't think about it, I just walk. If I think about it, I trip immediately.
These days, I think I'm spending about 25-40% of my time actually depressed, and the remainder of it merely 'unhappy.' I still can't think of any time in the past year or more when I've been able to answer the self-check with 'not bad' or 'happy.' This, of course, is not a good situation. But I think it's an important distinction, because I think the internal damage/mechanisms that result in depression are different from those that result in unhappiness (although depression itself can obviously result in unhappiness and unhappiness can contribute to the onset of depression). But I have this feeling that the reasons behind them are distinct enough that trying to 'fix myself' without understanding their differences is doomed to failure, because I can't imagine things that will fix *both* being possible (or even 'reasonable').
So maybe I should work on why I'm unhappy, versus why I'm depressed. Those seem more amenable to intervention, because they are much more clearly the process of a particular chain/pattern/habit of thought: when I ask myself how I feel, I run some sort of evaluative process, and come back with an answer. Thus, that answer isn't just 'innate' the way depression is.
It drives me crazy when therapists (or anyone else, really) ask me what makes me depressed, or what makes me think I'm depressed. Being depressed, for me, is like being oxygen starved. It's a state. It's not a result of anything internal. I'm depressed as a result of something or things I can't name, but I'm not telling you I'm depressed because I ran some sort of internal checklist. I'm telling you I'm depressed because it's a first-order answer - some thing or things outside my current conscious control and which I can't identify have deprived me of oxygen.
But unhappy? Different, I think.
Unfortunately, I think my therapist is also having trouble with this distinction, because he keeps trying to push me to apply changes in my ways of thinking to the problem of being depressed.
I'm oversimplifying quite a bit, here. One problem with just being 'unhappy' is that the longer I go being unhappy, the more of a failure I feel like when I do the evaluation - in other words, the longer the time period since I was last 'not unhappy' the harsher the input to the 'are you happy' question. I suspect this is because there is a 'are you successful' subroutine that gets called during the evaluation, and either/both the answer to that subroutine or the subroutine itself are depressing/broken.