my first therapist (a 60-something year old, german psychiatrist) i always called Dr. B....it just seemed appropriate. my second therapist...oddly, i dont recall ever addressing her. when i called the office or referred to her when speaking to someone else, it was Dr. <last name>

all my clients call me by my first name. i work in a residential setting though...its already much less formal. it would feel weird for them to call me Dr. some of them dont even know that i'm a doctor...a few weeks ago when some found out, they started calling me Dr. Awesome LOL