New Zealand did a "horrific job" looking after intellectually disabled people in state care, a report by the Human Rights Commission says.
"The mistreatment was systemic, enduring and an everyday reality for New Zealanders with intellectual disabilities who lived in institutions and special schools," the commission said, releasing the report on Thursday.
The study looked at the mistreatment of patients by staff in mental health facilities from the 1950s to the '90s.
Researchers from the Donald Beasley Institute recorded the stories of 17 patients who spent most of their lives in institutions nationwide.
Testimonies from victims spoke of a lifetime of physical, psychological and sexual abuse and distress, and a life devoid of love and family, Disability Rights Commissioner Paul Gibson said.
Alison, who spent half a century in state care as a patient, recalled her time in Kingsgate and Carrington hospitals in the report.
"[Being] locked up for weeks... dragged down the corridor by staff by the feet and the hair and they throw me into a seclusion room... They would ... throw you into an empty room ... slam the door and lock it and leave you there. You'd be freezing cold, you had no clothes on, no toilet facilities, no bed, nothing," she said.
She said she was sexually assaulted at knife-point by a male patient when she was 11 and made to drink her own urine while in seclusion.
Sexual abuse was a feature of almost the patients' stories, researchers said.
Staff members described patients being showered with fire hoses and beaten at the Kimberley Centre in Horowhenua.
"When you look at things that went on in this place, it was horrific. They were cruel, they were very cruel people," a staff member of 10 years said.
The report comes amid calls for the Government to initiate an independent inquiry into abuse of children in state care.
Mr Gibson said the findings highlighted systemic failures and a system that enabled abuse to continue unchecked for years.
"These are the stories of New Zealand's stolen generations," he said.
"I would like to give assurances to disabled people and their families that we have learnt the lessons of the past and that systemic abuse is not ongoing and will never happen again."