Quote Originally Posted by frimble3 View Post
Yes, I don't think anyone's advocating for you to get an old dog. But a young adult dog, one where you can see the personality behind the puppy-cuteness, and assess it's level of trainability, etc. is probably more in line with your needs.
If this is a comfort-animal, you have to see that you get on well together, which is hard to assess in puppies, as a healthy puppy loves everybody, and is interested in everything.
I am, as I've said, a cat person, so I'll try to keep this general.
Don't pick the boldest dog, or the shyest. You don't want a dog you can't control and you don't want some pitiful creature that is more scared of the world than you are. (I will not tell you how I know these particular things about dogs, but trust me on this.)
Find a good, reliable real-life advisor, preferably one who does dog training, or who is knowledgeable about support animals.

Very good advice here. I linked to the association of professional dog trainers up thread, and I really do suggest consulting with a trainer if you want this to be a comfort animal who accompanies you into public places dogs are not generally allowed.