In the Dark Abyss

I didn't hear at all from online friend yesterday.  Generally this means that OF (online friend) is struggling with the dark abyss of depression.  OF becomes extremely introverted, uncommunicative, holes up, a bear in a cave.  I wonder what thoughts are going through my friend's head, what is swirling around and around like leaves in the wind.  What questions and fears is my friend entertaining?