Very sad to hear this - he was one of the greatest talents alive. Just a couple of days ago I saw him on TV in a supporting role in a relatively minor movie ("August Rush" - 2007), and still, he was able to shine. To this day "Mrs. Doubtfire" remains my favorite comedy. And, as said before, if it was easy to snap out of depression, Robin would be the person to pull that stunt. The lesson to take is - it isn't. Plus, Robin Williams was bipolar, which can explain both his genious, and his "manic" performances.
Another giant bites the dust. RIP, Mr. Williams.
Eden