I don't actually say her name in session (maybe once or twice when i said something happened and I was like "Oh, C will like this!), but in e-mails I use her first name. She is also very casual and introduced herself to me by her first name. She is also an LCSW, though even if she had a PhD, I think she probably would still go by her first name.

My last T was a psychologist with a PhD, but referred to herself by her first name. In e-mails and in my head, she was Dr. D. I am not sure if it was because she was more formal, or that her first name is the same of my mother's so I was more wary to use it...but i never called her by her first name.