I think some animals produce a therapeutic effect in the humans. For instan dogs provide company and sense of security; They also offer opportunities for fun, play and relaxation. All this entails a decrease in the feeling of anguish that people with problems can feel.
Also equine therapy is very beneficial for people who have any problem related to the autistic spectrum.
All research refers to the benefits they produce in children with problems of socialization and behavior disorders
Therefore I think the therapy with dolphins will be just as good as the rest.