My T uses "client." He is in private practice in a non-hospital setting. I work in a hospital and we use "patient" there. Everyone does, not just the MDs. I prefer "client" regarding myself, as I think of patient as someone who is sick, and I don't see myself as ill. There are types of therapy that have the client assume "the sick role," so perhaps if this was the type of therapy the T did, the word patient would be used.