When I am unwell I get really vivid lucid dreams, but they are usually nightmares or at least a little dysphoric. I have a hard time figuring out if I'm awake or asleep, so I came up with tricks to test if I'm in a dream or not. What I do is drink water, and if it doesn't make my mouth wet I know I am dreaming. Then I can try to switch them so they aren't nightmares any more. I try to wake myself up, but that doesn't work. In case you were wondering, pinching yourself in a dream hurts, but does not wake you up. I only get dreams like this if I'm in a mood episode, up, down, or mixed. These days I don't dream much because of my meds, sadly because I like to dream.

I don't know if dreams are therapeutic, but I think there is symbolism in them that can give insight into things.