headcanon. ptsd is the only disorder that clara is aware that she has— it was the doctor who realised that she had it in the months after trenzalore, and having him tell her that this was what she had was all she needed.
while seeing a therapist could be helpful, there are many reasons why she won’t, with the reason she brings up whenever the topic is mentioned being ‘i can’t imagine it’ll be much use if i can’t tell them what the trauma was’. in truth, the biggest reason she won’t speak to a therapist is out of a fear of being judged— of being thought of as weak for how she’s been effected. she will never admit that to anyone, though.
apart from the doctor, the only person who has known about her ptsd is danny, as he also had it as a result of his time in the army. on occasion they have been known to talk about it quietly while laying together in bed, sharing strategies to cope with it, or just venting to the other ( or, sometimes, making jokes about it that they both know wouldn’t be accepted by those who don’t have it ). although danny knows that she has it, and how it effects her, she never did get around to telling him what caused it.