It may not be stimulant psychosis. Apparently, stimulants can induce psychosis in those who have a predisposition (her mother had two untreated episodes, the latter lasting a full year).

She professes to be happy and honestly appears to be happy and relaxed. According to her, her unhappiness and stress are the result of my anxious response to her claims of psychic powers and my worry when the spirit said she was being harmed. Of course, this has been exacerbated by my dragging her to her shrink against her will.

"I Am Not Sick, I Don't Need Help! How to Help Someone with Mental Illness Accept Treatment." sounds worth reading. I'll try it. Thank you for the recommendation.