The portion of the U.S. population institutionalized in public psychiatric hospitals is one-quarter that of Germany and one-eighth that of Japan. Under the mass deinstitutionalization that occurred in the U.S. from 1955 to around 2010, the portion of the U.S. population in public psychiatric hospitals declined by 96%. Per a 1997 academic book about “America’s Mental Illness Crisis,” “The magnitude of deinstitutionalization of the severely mentally ill qualifies it as one of the largest social experiments in American history.” About “763,391 severely mentally ill people (over three-quarters of a million) are living in the community today who would have been hospitalized 40 years ago.”