If said psychiatrist is any sort of professional, then yes.
If you were not comfortable in divulging that information until this point, then that is at your discretion. Irrespective of how pertinent the psy feels the information was to your recovery, in his or her eyes, you have only done yourself out of a potential quicker recovery that may have resulted from your speaking of the incident earlier.
What you are doing is very brave, and if the psy has any level of empathy, then your bravery will be upheld. They are trained to deal with this sort of thing. My advice would be to come out with it and let the chips fall where they may. I think you will be relieved by the outcome.
Either way - you are again doing something very commendable. In anticipation for your choice... well done Kmrekl.