Police have resorted to firing Tasers to subdue mentally-ill patients in hospital and care homes more than 50 times in three years, Freedom of Information requests have disclosed.

Charities have expressed alarm over the levels of Taser use and warned that it could aggravate the condition of people already suffering extreme distress.

The Care Quality Commission (CQC), the health service watchdog, has said Tasers should be deployed only as a last resort in psychiatric wards.

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However, The Independent has established from replies received under the FoI Act that English and Welsh police forces authorised Taser use against people receiving psychiatric care on 52 occasions in the last three years.

Leicestershire Police reported officers fired their Tasers 14 times over that period, 11 times while patients were being transported and three where they were being treated. They included occasions where police intervened to restrain a man wielding a knife and to stop patients threatening to self-harm.

Officers in Avon and Somerset used Tasers ten times to restrain people held under the Mental Health Act between February 2012 and February 2013. It also disclosed one person aged under 18 was Tasered in that period.

Greater Manchester police fired Tasers nine times and used them twice in “drive stun” mode, where the weapons are held against the target without firing.

Fifteen forces responded to requests for information about Taser use on people receiving psychiatric care. Others acknowledging its use included Norfolk (four times) and Essex, Gloucestershire, South Yorkshire and Surrey (twice each).

The national tally of 52 instances is certain to under-estimate the actual total as several large forces, including the Metropolitan Police, did not respond to the FoI requests.

In its most recent annual report, the CQC cited four incidents where patients were Tasered - two on a hospital ward and two who were being transferred.

It said: “It is of great concern a Taser was used within hospital premises in this way. It may be that the use of a Taser can never be ruled out in this context, but any incidence of its use should trigger a thorough consideration of whether the staffing of the hospital unit is adequate to maintain safety, both in terms of staff numbers and staff training.”

The Association of Chief Police Officers (ACPO) said that officers were trained to negotiate before they Tasered people who were often extremely strong and violent.

Deputy Chief Constable Simon Chesterman, ACPO spokesman on armed policing, said Tasers were often “less injurious” than alternatives such as physical restraint or the use of batons or sprays.

He said: “If the health service or care provider needs to call us to assist with a violent patient, we will have a duty to help.”

But Paul Jenkins, the chief executive of Rethink Mental Illness, said: “It is a sad indictment of in-patient care that police have resorted to using Taser guns on people who are in crisis.

He added: ”Police should be especially careful when handling someone taking antipsychotic medication - this medication can weaken the heart, meaning Taser guns can have potentially fatal effects on this group.“

Paul Farmer, the chief executive of Mind, said: ”Using them on people who are experiencing a mental health crisis and who are already displaying signs of distress, can make things even more traumatic.“