Normally when a celebrity passes away, I say a quick prayer for their soul and move on. Williams's death is different for me, and not just because I loved so much of his work. Depression claimed another life. In all the interviews and reflections I've read, nobody has had a bad word to say about him. That's a testament to the kind of man that he was.
People who have never experienced depression can never know. It stays with you even when everything appears to be going your way. Some people are able to carry on in such a way that not even their friends and family suspect that something's wrong. Williams spoke openly of his addiction to alcohol and drugs. Depressed people often turn to such things as a way to self-medicate. Those don't make it go away, but it temporarily dulls the pain.
You can't "snap out of it." You can't make it go away through sheer force of will. That's why it's so insidious: it saps your spirit, your will to push on. You feel alone even when surrounded by loved ones. It whispers in your ear that there's no reason to go on. You feel like you've always been depressed and can't remember a time when you weren't. You feel that you'll never not be depressed and life appears to be one meaningless occurrence after another. Tomorrow doesn't feel like a promise but a prison. Some people reach the point where death appears to be the only escape. I hate that old platitude, "Suicide is a permanent solution to a temporary problem." Suicide only sounds permanent if you believe temporal existence is all there is.
The Church used to take a dim view of suicides; indeed, she used to teach that they went straight to hell. It's an act where the murderer and the victim are the same person which at first glance seems to preclude the possibility of repentance. She's since softened that view a bit. Almost by definition, a suicide isn't in his right mind. Self-preservation is our most powerful instinct. The truth is, we never know another person's ultimate destiny until we're in the same boat so to speak. So say a prayer for God to have mercy on the soul of Robin Williams. He brought laughter to countless millions in life. Lord have mercy.