Most ppl who need service/guide/companion dogs/animals do not receive them. I think when I first had mine trained only 1 disabled person in 20,000 -who needed one - received one. The reasons? Not enough puppy raisers. Not enough money donated...not enough money in general. The cost of a service dog now goes well over the $10,000 value of my dog.
It's wonderful that someone is doing the studies to show that well trained animals can help the mentally unwell