The American Disabilities Act (ADA) defines a disability as “a physical or mental impairment that substantially limits one or more major life activities, a person who has a history or record of such an impairment, or a person who is perceived by others as having such an impairment.
The ADA doesn't specifically name all of the impairments that are covered.” It's possible for a personality disorder to constitute a legal disability, but a formal diagnosis is required, as well as substantial evidence that the disorder is sufficiently disruptive to the individual’s life.