Written Journals vs. Art Journals

There seems to be a war going on inside my journaling brain and I can't seem to resolve it.  I keep two types of journals, art and written, and I can't seem to mingle the two.

My written journals, which I have kept for years, are simple spiral bound notebooks with arted-up covers.  They hold my innermost thoughts, mostly negative and whiney.  When I'm wrestling with a problem, it gets worked out in my written journal.  When I'm angry, hurt or upset with someone, I can spew for pages in this journal.  It can get pretty ugly.  I don't intend for them to be filled with poetic prose or be a legacy for my children (God forbid!).  The contain all the rantings and ravings I would never want to say outloud.  That being said, writing in them sure makes me feel better.

My art journals are just that - places for me to experiment with different techniques and styles, and a catch-all for current and future project ideas.  If I'm in a dark mood, my pages tend to be dark.  If I'm in a light and happy mood, my pages are full of bright and cheerful colors.  The problem is, they tend to lack substance, i.e. words.  Every time I try to write in these journals, my words seem to be superfluous, shallow, empty.  I think this dichotomy stems from the fact that my written journals are private, for my eyes only.  But somewhere in the back of this crazy head of mine I think that someday something in my art journals might be published.  While I'm sure this is nothing more than wishful thinking, it paralyzes me with fear.  How much of myself do I want to put "out there"?

So my question is this:  What do you write in your art journals?  Do you intend for them to be public or private?  Art is most certainly therapeutic, but how do you deal with the dark stuff?