persistent low mood or loss of interest or pleasure in activities, along with four other symptoms occurring together for a period of at least two weeks, indicate clinical depression
taking your medication and get a good group of friends or some one who can cheer you up and do stuff! sitting around makes you bored and then you get sad and depressed so if you go out and do stuff...
Depression, in short, is as tangible as hell gets. I've survived a major episode of depression as well as a more recent dysthymia (mild depression). It involves a loss of interest in hobbies or...
I'm not sure whether you're looking for a textbook type answer or a personal experience, but i can give you some information on the latter. to keep things simple I'm going to leave out the physical...