A PSD letter states the animal is required due to the owner's disability. In addition, the letter must state that the animal has been trained to perform a specific task related to your disability.  Keep in mind that PSDs differ from ESA dogs. A PSD is trained to perform a specific task, rather than provide comfort like an ESA dog.  In other words, these tasks range from tactile stimulation to awareness.  Moreover, a disability, whether psychiatric or emotional, that limits an individual from performing everyday activities qualifies an individual for a PSD.