> Why would you mention the number of items on the scale, but not mention the number of points the drug gained? Is it that professionals normally refer to it as the "17-item Hamilton depression rating scale"?

Correct. "17-item Hamilton depression rating scale" (or HAMD-17) is the precise name of the scale; "17-item" is required to distinguish it from other variations with different numbers of questions.

The precise improvement in scoring is undoubtedly present in the clinical trial paper, but isn't relevant to a FDA press release about their approval of the drug.

https://dcf.psychiatry.ufl.edu/files/2011/05/HAMILTON-DEPRES...