Four people are to be charged with mistreating and neglecting patients at a mental health unit.
James Hinds, Susan Murphy, Julie Burge and Michael Barnard are being prosecuted following an investigation into staff at the Solar Centre, at St Catherine's Hospital in Doncaster, South Yorkshire.
The Crown Prosecution Service said the charges relate to 18 patients, both men and women, with the alleged offences taking place between 2005 and 2007.
Hinds and Murphy have been summonsed to appear at Doncaster Magistrates' Court on 28 August. Burge and Barnard will appear at the same court on 10 September.
In a statement, Richard Hebbert, lawyer in the Complex Casework Unit for CPS Yorkshire and Humberside, said: "I have today authorised South Yorkshire Police to commence proceedings for a prosecution against four people relating to the ill-treatment and wilful neglect of patients receiving treatment for mental health disorders at the Solar Centre at St Catherine's Hospital, Doncaster.
"They are James Hinds with 14 charges, Susan Murphy with 13 charges, Julie Burge with three charges, and Michael Barnard with eight charges. All four were working at the Solar Centre at the time the offences are alleged to have occurred.
"The charges relate to 18 patients, both men and women, and occurred between January 2005 and March 2007.
"A full review of all of the evidence in this case has been conducted and I am satisfied that there is sufficient evidence and it is in the public interest to prosecute."
Hinds is 58, Murphy is 43, Burge is 48 and Barnard is 49, the CPS said.
The prosecution follows a long-running series of investigations by South Yorkshire Police into allegations of abuse at the centre, which looks after people with learning difficulties.
The first investigation in 2007 concluded after the CPS decided there was not enough evidence to mount prosecutions.
Police reopened the investigation in 2010 after an inquiry by the Rotherham Doncaster and South Humber Mental Health NHS Foundation Trust (RDaSH).
But last year the CPS again concluded there was insufficient evidence to bring any prosecutions.
Wednesday's decision is understood to have followed a review.