The Ewell Epileptic Colony, later known as St Ebba's Hospital, was opened on 1 Jul 1903 by the London County Council. It consisted of nine villas and originally accommodated 326 patients. In 1909 two more villas were built and the number of patients was increased to 429. From 1918 to Jan 1927 the institution served as a war hospital and treatment centre for neurasthenic ex-servicemen and was administered by the Ministry of Pensions. In Feb 1927 it returned to the LCC as a mental hospital and was enlarged by a further two villas and additional outbuildings.
In 1930 the Mental Treatment Act permitted for the first time the reception of voluntary patients in public mental hospitals. St Ebba's was readily suited to this purpose and plans for the enlargement of the hospital were prepared. The extensions were completed in two stages, the first in 1936 and the second in Nov 1938. Many of the voluntary patients at St Ebba's were admitted after attendance at out-patient clinics at various teaching hospitals. Students from these hospitals attended St Ebba's to see cases and receive instruction on them and staff from St Ebba's held out-patient clinics in London
The selection by the LCC of voluntary or temporary patients with illness of recent onset and the further classification of patients within the hospital into separate accommodation facilitated by the villa system, encouraged the early admission of patients who might otherwise have been reluctant to accept psychiatric treatment in hospital for fear of being associated with chronic mentally ill patients. The result was that St Ebba's achieved good results with a large number of patients by retaining them for a maximum period of two years before transferring them elsewhere.
The hospital developed a good liaison with Wandsworth Prison and prisoners were seen at St John's Hospital and treated at St Ebba's if necessary.
In 1948 the Hospital became part of the National Health Service and was governed by St Ebba's and Belmont Hospital Management Committee. The HMC answered to the South West Metropolitan Regional Hospital Board who decided to abandon the cental admission arrangements for mental hospitals operated by the LCC in favour of local autonomy within a defined catchment area. In view of the special part played by St Ebba's in the psychiatric service for London the Board's Mental Health Committee recommended that St Ebba's should not have a defined catchment area but should remain available to the London area of each of the Metropolitan Regions with the exception of that for the North West.
A special unit for the treatment of adolescents was established at St Ebba's in 1949.
Successive physicians at St Ebba's developed an interest in the endochrinological aspect of psychoses and undertook considerable research in this field. Early in 1961 a joint appointment was made by the Board and the Medical Research Council of a consultant to work at St Ebba's in connection with the MRC's Neuropsychiatric Unit at Carshalton.
In 1962 the South West Metropolitan Regional Hospital Board changed the use of St Ebba's Hospital from a psychiatric hospital to a hospital for mentally subnormal patients. The change came into effect on 27 Feb 1962 and psychiatric patients ceased to be admitted on 17 March.
Upon changing its use in 1962, St Ebba's was attached to the Fountain and Carshalton Group. The headquarters of this group was the Queen Mary's Hospital for Children at Carshalton. Other hospitals in the group included the Ellen Terry Home and Brooklands Home in Wray Park Road, Reigate, Osborne House at 245 The Ridge, Hastings, East Sussex, and South Side Home and The Turret which were in Streatham.
Upon the reorganisation of the National Health Service in 1974 the constituent units of the Fountain and Carshalton Group were included in the St Helier Hospital and Queen Mary's Hospital District of the Merton, Sutton and Wandsworth Area Health Authority. All of the units, with the exception of Queen Mary's, were outside the geographical area covered by the district and so were managed on an extra-territorial basis. The Ellen Terry and Daffodil Homes closed in Apr 1986. For records of Queen Mary's Hospital, the Ellen Terry Home and Brooklands Home see below, 6292/34/-.
On 1 Apr 1982 Merton and Sutton Health Authority was formed from the former Merton, Sutton and Wandsworth Area Health Authority and St Ebba's was included within the new administrative area to serve Merton and Sutton, Richmond Twickenham and Roehampton and Wandsworth Health Authorities. In April 1990 responsibility for St Ebba's was transferred to Mid Surrey Health Authority. In 1991 Mid-Surrey Health Authority's Mental Handicap Services Unit applied to become an NHS Trust and this was granted in April 1995 with the creation of Surrey Heartlands NHS Trust. St Ebba's Hospital now forms part of Surrey Heartlands, providing a residential service to over 360 people with learning disabilities.