Have you ever heard of or considered trying TMS (Transcranial magnetic stimulation)? I went to a psychiatrist who had all of the equipment to do it in his office. He wrote several papers about it's effectiveness. You would have to go for 5 days straight for a treatment and do that for a few weeks. It is supposed to be very helpful for depression and the doctor said it would help with mixed episodes also.

https://psychnews.psychiatryonline.o...pn.2017.pp11b3