Mental health experts blame lack of resources, a rise in drug abuse and increasing worries about protecting the public.

The Department of Health says the number of formal admissions to hospital under the Act rose from 16,000 in 1988-89 to 27,100 in 1998-99.

The vast majority of these - some 89% - were people admitted to NHS hospitals under Part II of the Act which deals with emergency admissions and admissions for up to 28 days and up to six months.

The number of men sectioned under Part II rose from 6,200 to 12,300 over the 10 years, while the number of women increased by about 48%, from 8,100 to 11,900.

In 1998-99, 20,500 people were sectioned under the Act after admission to hospital as voluntary patients.

As of 31 March, there were 13,000 patients detained in hospital of which 1,300 were in high security psychiatric hospitals, 10,500 in other NHS facilities and 1,200 in private mental nursing homes.

Lack of resources

Matt Muijen of the Sainsbury Centre for Mental Health said: "The increase is a genuine reflection of how demanding mental health has become. It is more complex.

"Interventions are taken later and later because of a lack of resources and beds and we are living in a more demanding and violent society where people are showing increasingly challenging behaviour."

He added that the threshold for admission to hospital was being raised higher and higher because of the bed shortage and, at the same time, many community care services were not able to cope with the more seriously ill people they were having to treat.

The increasing focus on protecting the public, following a series of killings by mentally ill people living in the community, could also have contributed to the rise in forced admission to hospital, he added.

"In the last couple of years, staff have become very defensive. Mental health workers are playing safe." In addition, he said the increase in drug abuse over the past 10 years had played its part since drug abuse was strongly related to mental health problems.

'System in crisis'

"The mental health system is in crisis and services are at breaking point. We welcome any new money being put in by the government, but there is unlikely to be a dramatic improvement in the near future and with the money being put in at present we are unlikely to be able to return to the levels of 10 years ago," said Mr Muijen.

The government has made several recent announcements of extra cash for community care, emergency beds and other mental health services, including £700m over the next three years for its "third way" for mental health.

Mr Muijen said it would need an extra £500m a year to provide a very good service. "In the absence of this, priorities have to be made," he stated.