Pet Therapy For Your Mental Health

I heard about this actually. My auntie was dealing with depressions, and anxiety too, and her therapist recommended trying this treatment method. I am curious actually what pets do they use. Because I heard about dogs, but can there be exotic support animals? Not only that, but I am starting to study the exotic pets world, and I am interested if there can be therapies with snakes or lizards. I am sorry if my questions can sound stupid, but I am too curious to not ask this. Have a nice one guys.