There’s a book called Tabletop Role-playing Therapy: A Guide for the Clinician Game Master by Dr Megan A. Connel that’s a really standout resource about this, she appeared on the official D&D podcast a year or so ago talking about it.
I’d say that this is more a resource for therapists to use TTRPGs than it is for DMs to act as therapists for their players. There’s a fine line between accommodating your players’ preferences and needs and providing unwanted therapy; if you want to actually put any therapy techniques into your game, ask your players approval first.
I just went looking for this. Here’s a link to the podcast for everyone else: https://pca.st/episode/b8388458-0062-47c5-a259-fae295a45305