Then, when I booted up livejournal, I noticed two things: firstly, that someone has taken me off zir friends list (possibly because I post so much heavy stuff here), and secondly that someone I care about is having a truly awful time at the moment. Reading her emotionally heavy stuff lets me relate to the person who can't deal with my heavy stuff - it is very hard to know what to say or do at times like this, especially when the other person is emotionally close but geographically distant, and you're reading what zie's said in the middle of the night, and you don't know whether zie's ok or not.
So, two practical suggestions. Firstly, a message to any of my friends who ever get seriously depressed (probably in the region of 50% of you - I seem to select for depression). The night I had a nervous breakdown, I made panicky phone calls to friends at 3am. Talking to people who cared about me pulled me back from the brink. Just in case I haven't made this clear before: anyone who has my mobile number is welcome to ring it any time of day or night. If it's on, I'm awake. If it's not on, leave a message. If it's urgent (if you're suicidal or despairing) ring my land line. If you don't have the number and you think you might need it, email me to get it (we're not in the phone book).
Secondly, Richard once wrote a piece of prose about loving someone who's in despair. I never know what to say to comfort someone in that sort of state, but maybe reading that might help.