The other day I recommended to a friend a simple way to elevate your mood when you're feeling down. Depression is a complex illness, it comes, it goes, you tend to have bad periods and good. Sometimes it comes in sudden attacks which can be kind of frightening.
I won't take the drugs that people talk about. Had a bad experience and found out that I'm contraindicated. I can't say yay or nay on the drug issue for other people though. Way outside my range. But I do know there are a lot of simple things you can do to just plain make yourself feel better, some of them are long term (green vegetables and exercise cures nearly everything) some are good for a quick lift.
The quick ones I like best are going for a snorkel in the Mediterranean (I realise that this is less of a quick-fix option for others though) and a bike ride. The other day, I had got caught by the Gravity Ray and knew I had to do something to break free. Pushed my bike up the hill with a collecting bag and five yogurt tubs and collected four and a half pounds of blackberries and made some jam.
But if you are really stuck, and can't tear yourself away from the comforting glow of the internet, that's OK. The internet can be a useful tool. I recommend fifteen minutes of funny videos on YouTube: