The Metropolitan police owned up yesterday to stigmatising people with mental illness and "perpetuating a myth" that they are especially prone to violence. It promised a programme of reform to stop the inappropriate use of police cells to detain vulnerable people who are going through a mental health crisis.

Officers said damage was often done by unauthorised leaking of mental health records, giving a misleading impression of suspects' danger to the public. There were also problems if uniformed officers accompanied social workers in detaining a patient under the Mental Health Act.

A review by police and NHS chiefs in London said: "We recognise that people who experience mental illness are far more likely to be a victim of crime than a perpetrator."

Brian Paddick, deputy assistant commissioner, said holding violent patients in police cells protected other people but did nothing to protect them against themselves, or to care for their clinical needs. He promised training to educate officers about the need for patient confidentiality.

The police and NHS organisations agreed to set up a network of "places of safety" across London where people in a mental health crisis could be treated.