Inkblot
From my own experience people can be very judgemental about emotional issues. Not only that, but because they do not have all the facts about certain conditions their judgement is usually harsh and ignorant. There really is no reason to tell this person about your PTSD, but this has to be your own choice. This is merely a suggestion and my opinion from past experience with others. Just telling someone at one time that I was seeing a therapist made me feel as if I was some crazed lunatic. A lot of people just don't get it. Those who were abused are going through a different life cycle then those who weren't and I feel that the only ones that truly understand are the people who "have been there"
Good luck with your decision.
4hope

You are of God little children and have overcome them, because He who is in you is greater than he who is in the world. 1 John 4:4