I also think that doctors tend to dumb-down and downplay the actual truth of the effectiveness of treatments. Partly because for the majority of patients, being told that a treatment is realllyyy good can actually make it more effective, by the placebo effect. It also makes the patient happier and more confident in the abilities of the doctor.

I noticed that since I got "Dr." put in front of my name on my medical records, doctors tend to firstly ask what I'm a "Dr." in, and secondly tell it to me straight.