To corroborate #2: One of the things often said about depression and suicide is that severely depressed people are too depressed to have the energy to commit suicide. It's only when they start coming out of the pit and feel a little better that they'll get the nerves. That's why depressed people are (or at least should be) monitored like crazy when you start giving them antidepressants. It's a cruel irony, but making a depressed person feel better can actually make them more dangerous to themselves. Unfortunately, people see their friends and family starting to claw their way out from the pit of despair, so of course they seem "so happy" (comparatively).