I always thought Tony’s psychiatrist, Dr. Melfi, was an honorable character. Remember when she was raped by that punk and she was so so close to telling Tony what happened. Knowing that if she did, Tony would’ve had that punk whacked before the sun went down. But she kept it to herself.
However, she did blab about Tony, violating Doctor/patient confidentiality, with her psychiatrist and with her family.
That was one of my favorite episodes, I think deep down we wanted her to tell Tony. But she was happy just in the knowledge that she could if she wanted to.