That's true. Also, I attended some counseling sessions in college with psychologists. It was free, included in tuition, so I figured why not. Asking about their policy, they said they're allowed to discuss patients with the other psychologists within the office, especially if they need a second opinion or someone else specializes in a certain field.
Funny story: One day, I'm getting out of a late session in the back office. All the psychologists must have been waiting in the waiting room for our appointment to end in order to leave. I believe it was the last day before winter break. As I'm walking up the hall, I hear one say "The thing is, he's really...just kind of..." then another chimes in and says "messed up?!" They all erupted into laughter 1 second before I rounded the corner. Once I was seen, they immediately became quiet. I was smiling big and almost laughing myself while shaking my head. My mild suspicion was confirmed that they quite possibly sat around gossiping about patients. I also think the fact I reacted positively put them at ease - I thought it was funny. I'll never forget that.