The Supreme Court decided under Title II of the ADA that mental illness is a form of disability and therefore covered under the ADA, and that unjustified institutional isolation of a person with a disability is a form of discrimination because it "...perpetuates unwarranted assumptions that persons so isolated are incapable or unworthy of participating in community life." The court added, "Confinement in an institution severely diminishes the everyday life activities of individuals, including family relations, social contacts, work options, economic independence, educational advancement, and cultural enrichment."
Part of Title I was found unconstitutional by the United States Supreme Court as it pertains to states in the case of Board of Trustees of the University of Alabama v. Garrett as violating the sovereign immunity rights of the several states as specified by the Eleventh Amendment to the United States Constitution. The Court determined that state employees cannot sue their employer for violating ADA rules. State employees can, however, file complaints at the Department of Justice or the Equal Employment Opportunity Commission, who can sue on their behalf.
The Department of Justice published revised final regulations implementing the Americans with Disabilities Act (ADA) for title II (State and local government services) and title III(public accommodations and commercial facilities) on September 15, 2010, in the Federal Register. These requirements, or rules, clarify and refine issues that have arisen over the past 20 years and contain new, and updated, requirements, including the 2010 Standards for Accessible Design (2010 Standards).