In case you are wondering my treatment approach

Some probably think what a smarty pants I am, so what would I actually do if I were the therapist? For example, how would I have treated the woman who was Jung's patient who thought she has lived on the moon. Obviously I don't know the facts beyond this anecdotal story of the type and extent of her illness and other symptoms. But here is what I would do if I were presented with a woman who, due to mental illness, felt she had been on the moon. I would treat her as if she had indeed been on the moon and then guide her through behavior and cognitive therapy that would utilize the model that she is now fully "relocating" to earth. I'd have her intercept thoughts about her moon experiences with thoughts about how she's packing away photos she took of those times, for example, as she's now fully living in her apartment (or clinic) here on earth. Whenever a moon event would arise in her mind I would incorporate it into her doing both mental and real activities that relate to her making a "permanent change in residence" here on earth. For example, she could use art therapy to draw her "moon passport" and her "earth passport" and then work on canceling and filing away the moon passport since she will no longer need it. So while she would be having the mainstream treatment for whatever her baseline illness is (e.g. schizophrenia) I would transition her behavior and cognition from the delusional ones to the reality using tools such as envisioning her relocating to earth.

Hope this helps.