BBC's James Westhead: Some left more distressed than when they came in

The report by the Sainsbury Centre for Mental Health also found that one in 10 people is admitted solely for social reasons, for example, because they have no-one at home to look after them.

One in five is staying too long on the wards because less expensive alternatives are not available.

The charity is calling for an urgent review of emergency psychiatric care.

It wants care to be patient-centred and says this will cut costs by ensuring patients are not unnecessarily held in hospital - the most expensive form of mental health care.

Acute care is designed for short-term crisis care only.

A vacuum of care

The report, Acute Problems, looks at the experience of 200 patients' experience of admission, treatment and discharge from wards.

Dr Matt Muijen, Director of the Sainsbury Centre, said: "There is a tremendous shortage of personalised care that everyone has a right to expect.

"For many people, their experience of acute in-patient care can only be described as a vacuum instead of a therapeutic environment dedicated to the needs of the individual."

The report found that:

• 30% of inpatients were not given anything to do in hospital, whether recreational or therapeutic
• more than 10% were admitted for social reasons, such as a lack of support at home
• most patients stayed longer than they needed to because of a shortage of community care facilities
• almost every ward was full to capacity, with more patients than beds
• many patients felt unsafe on the wards, particularly women
• discharge from hospital was often unplanned with community services not being given adequate information.

One in four

Up to one in four Britons seeks help for mental health problems every year with up to 4% of the population suffering severe mental illness.

Hospital care swallows up two-thirds of the mental health budget for adults. Treating a person in hospital costs around £50,000 a year, compared to £12,000 a year for community care.