If I trusted my doctor and my doctor discussed with me why they wanted to work with my therapist, what they thought they could gain from it and I thought it would help them, I would consent.

These things are medical records and if I have depression, say, I want my other doctors to know this as illnesses are very rarely self-contained unless you break a bone or something? People with heart disease get anti-depressants and anti-depressants can cause older people to black out/fall down (my 94 year old aunt had that problem, some doctor had prescribed the anti-depressant for a heart problem but it took a neurologist reviewing all her meds to realize that no one bothered to stop its use when the problem was over).

The more information a doctor has on you, all of you, the better able they may be able to help, even to the point of saving your life. I almost died because I'd never been ill before when my appendix burst in 2003, did not have any doctor besides my dentist, and so the doctors had nothing to go on as to how I would react to medicines and other treatments, we did not know my body. Now I see my doctor quarterly and have been for 5+ years, building up the relationship and the notes/file so it will all be there the next time it is needed and they have a mystery on their hands!

It's a body, it's not "You"?