I have a service dog for PTSD and anxiety. The differance between an ESA and a sd is that a sd HAS to be trained to do something (task or work) that you can't do for yourself. My girl body blocks people from getting to close, reminds me to breathe and grounds me when I have a bad panic attack. ESA can't go into stores or restaurants with you but a sd can. The registries like the one posted above are scams, you cannot be asked for certification for your sd bc the ADA does not recognize any certification. That being said, think really hard about what it's like to bring a dog everywhere you go. The extra time it takes to do everything and the people that stare at you. Sd are also expensive! It can cost around 20 thousand to get one already trained! If you do the work yourself to train the dog it's cheaper but the dog has to be solid on all commands and show no reaction to almost everything. Most dogs fail unfortunately.