Three staff from a private hospital near Bristol have pleaded guilty to the ill treatment of residents.
The case follows secret filming by the BBC's Panorama TV programme at the Castlebeck-owned Winterbourne View hospital near Hambrook.
Wayne Rogers, 31, and Allison Dove, 24, both of Kingswood, admitted to nine and seven charges each and Holly Draper, 23, pleaded guilty to two charges.
The programme showed patients allegedly being physically and verbally abused.
Both Rogers and Dove pleaded not guilty to one charge each under the Mental Capacity Act, which was accepted by the Crown with the charges resting on file.
The court heard the offences were committed between February and March 2011.
Judge Michael Longman released all three on bail to await sentencing at a later date.
At the same hearing, Michael Ezenagu, 28, of Malabar Court, India Way, London, pleaded not guilty to three counts of ill-treatment.
Neil Ferguson, 27, of Emersons Green, Bristol, pleaded not guilty to one count of ill-treatment.
No pleas were entered by Graham Doyle, 25, from Patchway, Jason Gardiner, 42, of Bristol, Charlotte Cotterell, 21, from Yate, Kelvin Fore, 33, of Middlesbrough, Sookalingum Appoo, 58, of Bristol and Danny Brake, 27 of Bristol.
They will have their cases dealt with on 16 March.
Twenty-four patients were transferred from Winterbourne View following the investigation and the home was closed last June.
A spokesman for Avon and Somerset Police said a further three people who were arrested during the investigation will not face charges.