Traumatic brain injury.
Post Traumatic Stress Disorder.
Yes. There are service dogs for each of these and many more diagnosed physical and mental disabilities, disorders and diseases.
In the U.S., service dogs can go almost anywhere their handler goes. Service dogs are not pets and a "no pets" policy does not apply to them.
Are not service dogs. They are well-trained family pets who, when invited, can visit people in hospitals, nursing homes, schools, libraries, etc. Therapy dogs are otherwise allowed only in places the family pet is allowed. "No pets" policies apply to them.
Are not service dogs. Do NOT pretend that your beloved Fifi is a service dog so she can go to dinner with you. It's immoral and a slap in the face to "real" service dogs.
This, dear readers, is only the tip of the iceberg. If you think a service dog is right for you, start your search for information at Service Dog 411. Or drop them an email. And take a moment to read some great real-life dog stories.
Woofs 'n wags!