No one knows what the board considers "sufficient". I don't really know what your case is about, that's why I didn't comment on your other threads. Outside of the context, heart notes from a therapist would not be considered a professional communication, but I am not sure if this would be enough to make a therapist face some serious consequences. Most likely, not. Again, everything depends on the context, which I am not familiar with.

Generally speaking, the more evidence you have, the greater there is a chance your complaint will be taken seriously, and, conversely, the less evidence you have, the less likely the board would proceed to investigate it.