I assume you already discussed this with your players – I know that in my main player group just 2 of the 8 are willing to GM regularly, some will do oneshots, but also some freak out by the thought of having to lead a session.
I like the episodic approach, I've been thinking about that for my 2nd group since we only play once per month and it is hard for most to remember story elements that happened two or more sessiona ago (and note taking is hard 🤔).
On the other hand I like having some sort of continuity that might turn into an overarching story later on. Things like recurring NPCs, friendly or villainous. If there is no continuity at all, I fear it might turn uninteresting rather quickly.
But 'monster of the week' is an existing format (there's even a published game by that name)
Ttrpg's can definitely be used by therapists (e.g.see https://gametogrow.org/ ) but people in general should not underestimate the skill and training professional therapists bring to the table. Just playing an rpg is not therapy.