Norwich State Hospital opened its doors in 1904 to 95 patients situated in one building on over 100 acres. The institution practiced the belief that restraints were more effective to patients than medication, and often practiced hydrotherapy as a treatment option. The patient population quickly ballooned and it became obvious additions to the hospital were needed, with two more buildings built in 1905 and a third in 1907. Over the next few years many additional buildings such as a staff house, maintenance shop, laboratory, main kitchen, and employee club house were built. The hospital population peaked in 1930 with a patient populatioon of 1,115 patients.

World War II hit the hospital particularly hard in the staff department, with a reduction of almost 57 percent in workers. By the end of 1950 the daily census had reached 2,799 and many more new buildings were added to the complex.

Norwich had a habit of constructing many new buildings and abandoning old ones at the same time. It is because of this that most of the abandoned buildings on the property were never all occupied simultaneously. By 1959 the hospital had managed to grow to over 900 acres.

Beginning in 1972 the hospital began a slow decrease in population. This can be attributed to shorter hospital stays, new methods of alcohol and drug and patient care which did not involve mental hospitalization, and increased crisi invervention. The population continued its decline until the early 90s, when its doors were forever shuttered.

Fairly recently VH1 filmed an episode of a show called "Celebrity Paranormal" in Norwich Hospital (renamed Warson Asylum). The cast included Tony Little, Godfrey (comedian), Rachel Hunter (model), Traci Bingham (playmate/reality star), and Ethan Zohn (Survivor). The cast was supposed to investigate the supposedly most haunted areas of the hospital and decide which was most haunted: The Theraoy Room, a Padded Cell, the Hydrotherapy Room, or the Operating Room.

VH1 managed to trash the front of the administration building by throwing furniture down the stairs, because the front desk didn't look haunted and abandoned enough, and they also created the so-called "padded cell" themselves- there actually was no such thing in real life mental hospitals, ever. The padded cell VH1 made was created from old couch cushions, covers removed. The covers were stashed in a closet 8 feet away.