A hospital for adolescents with mental health problems has been placed in special measures by inspectors who found patients sleeping on floors and sharp objects left in isolation rooms.

St Andrew's Healthcare's Fitzroy House in Northampton was rated inadequate by the Care Quality Commission after visits in March and April this year found safety had deteriorated over the past two years.

Inspectors said staff "did not always treat patients with dignity, compassion or respect" and raised concerns about the treatment of patients in segregation and staffing levels.

In response, St Andrew's Healthcare - which supports up to 100 young people with mental illness, autism and learning difficulties - has temporarily closed its child and adolescent mental health service to new admissions.

"The majority of seclusion rooms did not have basic furnishings such as a bed, pillow, blanket or mattress, and records referred to patients as sitting of lying on the floor while in those rooms. "On one occasion, staff did not respect a patient's privacy and dignity when changing her clothing. While female staff were present, there were also male staff there at the time. It was the inspection team's view that this was uncaring, undignified and disrespectful to the patient."

Paul Lelliott, Deputy Chief Inspector of Hospitals, Care Quality Commission.

Inspectors were particularly concerned by the deterioration of safety and the way patients in long-term segregation were treated.

They found sharp edges on door frames, sharp pieces of exposed metal, and blind spots in seclusion rooms.

Staff failed to review patients in segregation, did not complete care plans, or inform the local authority about people being cared for in isolation. Three patients had been secluded for longer than necessary at the time of the inspection.

The CQC praised St Andrew's for the range of therapies it offered to patients and was impressed with the hospital's facilities. Inspectors also found outstanding support for LGBT patients and a diverse workforce.

But the hospital has been handed a list of improvements it must make - from improving staffing levels, correctly following the Mental Health Act Code of Practice, and improving food hygiene.

Katie Fisher, Chief Executive of St Andrew's Healthcare, said she deeply regretted that its standards had fallen.

But she pointed out that the inspectors had found examples of good care.

"With particular reference to process surrounding seclusion and long-term segregation, we accept that we should have done better by our patients. We need a bigger rethink of our seclusion and long-term segregation process, so have begun a charity-wide review.

Katie Fisher, Chief Executive, St Andrew's Healthcare