Well said bailey.... have some rep.

I would say that it is not a legal aspect if your fired for PTSD because it is affecting your work, because whilst you are covered one way, your not many others, in that an employer cannot lose money carrying a person who is not performing their duties as agreed, illness or not.

If you had PTSD and you performed your duties IAW your agreement, and they fired you because they found out you had PTSD, and they knew someone who had it and beat people up, then that is grounds for legal recourse.... not just because you have it. If it affects you, it is a legal defence that you are at fault regardless the illness for failing to perform, turnup on time, address others in a civil manner, etc etc etc.