Depression, My own little explanation

I get to this subject at least once a year, and it's one topic where I can easily lose my own temper, so I'll try to write a complete explanation of the concept of depression. I'm not talking about a passing condition, a sort of "I don't feel well today", but of real clinical depression. But before any sort of explanation, there is a very nice article on Wikipedia on the subject:
Clinical depression

But the article in Wikipedia doesn't address the common misconceptions on depression (It's not the purpose of a encyclopedia) so I'll try to debunk a couple of those...

First of all, it's not something which can be easily 'fought out' or 'overturned'. It's a condition that slowly drain all the motivation or energy of someone, the very thing required to 'fight' the condition. It's like trying to run with chains attached to both feet. So someone depressive is not like that because he is too lazy, he instead lose any interest in why he should do anything.

Second, a depressed person can be really difficult to understand. Irritability is one of the symptoms and it can make someone very unpredictable. They will get angry or upset for the most irrelevant things, and wonder why they got angry 2 minutes later. Some will have a "I just don't care attitude" which can be a real pain. Others will simply pretend everything is all right, while still acting strange (The "Everything is fine, leave me alone" attitude).

Third, depression may not be because of a particular event, but be rather a large accumulation of smaller more insignificant reasons, or sometime for no particular reasons at all. Stress, strain, loss of sleep, diminution of daylight, etc.: a lot of factors can contribute to a depression, and they are not always visible at first. It is also important to note that it's not the nature of the events, but rather the perceptions of these same event that count.

Last but not least, don't treat a depressed individual like it's their fault. The "It's all in your head" or "Just cheer up" remarks only help to make the depressed one guilty about his own condition, which in turn, doesn't help at all. Social stigma is the worse thing anyone can give to any individual suffering from any form of mental illness.

Of course, this is all from my own experiences over the years... I'm pretty sure there are others I'm simply missing, but I think it's a good start.

If you would like more information on the subject of depression and metal illness in general, see the Mental illness foundation's website