I disagree with the information below. Any medical professional can prescribe an emotional support animal. Just like any medical professional can prescribe anti-depressants.
https://www.psychologytoday.com/blog...rowing-problem
***The Air Carrier Access Act
My daughter’s friend who snagged a free trip to Asia for her dog did so under the auspices of a different federal agency–the Department of Transportation. The DOT regulations differ from the Americans with Disabilities Act in several important respects. First, unlike the ADA, the Air Carrier Access Act gives legal standing to animals whose sole function is to provide emotional support. This means that, unlike service dogs, emotional support animals are not required to be trained to perform specific tasks. It’s enough that they are necessary for your psychological wellbeing. Thus your lovable pet puppy may well be entitled to free air travel if she helps you get through your day.
But don’t get too excited just yet. In some ways, the rules for emotional support animals are more rigorous than for service dogs. That’s because the feds have given airlines considerable flexibility in what is required of passengers who claim they need to be in the company of their emotional support animal.
Take Delta Airlines. If you claim to need four-legged emotional support to stave off a panic attack on your next flight, you will need to provide the airline with a signed letter from a “licensed mental health professional” (your family doctor will not do the trick). The letter must include the professional’s address and phone number, and it must state that you have a disorder listed in the fourth edition of the Diagnostic and Statistical Manual of the American Psychiatric Association. Further, you have to be under active treatment for your disorder by this “mental health professional.” The good news is that this letter, however, will allow your pet to accompany you in the cabin of the plane for free for a year.
The AACA differs from the ADA in another respect as well. Emotional support animals are not restricted to dogs. So if it is okay with the airline, you can bring your iguana along on the ride to calm your jangled nerves. I would advise, however, against becoming psychologically dependent on a Great Dane; emotional support animals flying on Delta are required to fit under their owner’s seat.***