I've kept a journal for like 25 years. A mistake I made with it, that I've only corrected this past year, was that I used it to indulge in my negative thoughts. I wrote them down, elaborated on them, and this made them more real to me. Instead of letting my negative thoughts pass through my mind and go away (because they aren't real most of the time), I captured them and recorded them as though they were the truth about me. The problem was that I did not have objectivity. I really believed them, and recording them made them more powerful.

I would just caution you, if you are writing depressive, negative stuff, that you need to look at what you write in the context of your mood at the time. If you are aware that you are depressed, and you write some horrible things about yourself, you really need to understand that what you're writing isn't true, it's your depressed mind kicking out meaningless static because it's on the fritz. Same with inflated manic thoughts.

When I'm deep in an episode of one extreme or another, I'll write a lot and believe that I'm discovering really profound truths about myself. When I look at it later, I realize I was just spinning out on some twisted idea I'd come up with. But believing in that idea probably led me to wallow or obsess and made my situation worse.

I just wanted to share that because I realized after many years that the way I used my journal was detrimental to me. I took several months off journaling while I went through intensive therapy, and a few months ago I picked it back up and have been using it constructively ever since.

The key for me is being truly honest with myself and not believing everything I think.