That would help, but metadata is a powerful thing. The relations, tendencies, and activities of someone, particularly the kind of notes (I imagine) are kept for therapy subjects, would be a treasure trove even with some subject indirection.

That tends to not work very well: https://www.nytimes.com/2006/08/09/technology/09aol.html

Unfortunately you need surprisingly little data to uniquely identify someone. For example, sex, date of birth, and zip code can uniquely identify a large swath of the general public.

http://latanyasweeney.org/work/identifiability.html

So removing the unnecessary date of birth and zip code, problem solved.