Many patients were unhappy with their wards

The charity Mind also found 29% were dissatisfied with the state of repair of their ward, and 28% with standards of cleanliness.

Mind is calling all patients to be treated in a therapeutic environment.

It warned that lack of activities leads to boredom, which causes frustration and slows recovery.

We rely on hospitals to help us get well, but at the moment many are not providing a therapeutic environment Paul Farmer, Mind

The average mental health inpatient stay is 58 days - nearly 12 times longer than the average for patients with physical problems.

A report by the Healthcare Commission, published last year, found that standards of cleanliness were poorer in mental health hospitals than in acute units.

Garden access

Mind said good ward design could play a crucial role in providing a calm and therapeutic environment , as could access to gardens and other green spaces.

But its research had found access to gardens was being used in some wards as a reward for good behaviour - and being denied as a punishment.

Mind is calling for service users to be involved in the design of new hospitals, and for all wards to be maintained to the highest levels of cleanliness.

The charity also said that all patients should have access to green spaces and single sex sleeping accommodation.

Chief executive Paul Farmer said: "Going into hospital with mental health problems can be very traumatic.

HAVE YOUR SAY I was detained first by an untrained agency worker and then by seven staff Ron, Bishops Stortford