I'm technically diagnosed depressive, but I've been asked to journal as of recent because it's been suspected that I might be bipolar spectrum. I notice that, when my moods are elevated, it helps to an extent because I have a place to pour my racing thoughts and it almost acts like a compulsion for me as well. The downside I find is that my thoughts move way faster than my hand and I get impatient and mad at my hand and journal and forget things. Then I'm frustrated at myself more. Of course I usually do stream of consciousness stuff? It might be different if you're doing creative journaling like poetry.