Panic attacks are symptoms and triggers of some disorders.
A good example is Obsessive Compulsive Disorder. If an OCD sufferer fails to complete a ritual, they begin to have a panic attack until they are able to repeat the ritual.
Schitzophrenia, Depression, Dissociative Identity Disorder, Bi-Polar Disease... they all have panic attacks associated with symptoms. Like I said.. I am not even touching a diagnosis. Not until I get my doctorate.