If you could, please let me know which, if any, of the following would be okay by you (please include character and journal names if answering for more than one in a comment):

1. Can he verbally psychoanalyze your character, e.g. turn bits of conversation into mini-therapy sessions?
2. Can he fear gas your character?
3. If yes to number two, is it okay for him to set up character-specific fear scenarios?
4. Would you be interested in using your character as a research specimen?

If there is anything in particular that you'd like to play out with the good doctor or his alter-ego, drop me a line here!