He was one of a rare breed of doctors, a clinician who devoted himself primarily to the advancement of medical knowledge while holding a full- time post in the National Health Service. He was appointed consultant physician to the Joint Bethlem Royal and Maudsley Hospital in 1957, a title traditionally given to consultant psychiatrists at this postgraduate teaching hospital whose origins go back to the time of Henry VIII.
He adopted an exemplary personal style in his researches and worked largely single-handed. He began with observations which had escaped the attention of others, often because they appeared too commonplace. He then systematically pursued two or three main themes doggedly over the course of several years, applying his own kind of disciplined scholarship and reasoning.
The son of a Church of England clergyman, Hare read Biochemistry at Gonville and Caius College, Cambridge, and then decided to study Medicine, completing his medical degree at University College, London in 1943. He soon entered psychiatry and distinguished himself by winning the Gaskell medal of the Royal Medico- Psychological Association. He decided to concentrate on epidemiological psychiatry and confirmed the high rates of schizophrenia in the central parts of Bristol, in order to test the hypothesis that schizophrenia is caused by social stresses.
He later showed that patients who suffered from the major psychoses, including schizophrenia, were more likely to have been born during the first quarter of a year when compared with the normal population. He concluded that winter-born children are prone to nutritional deficiencies or infections which in turn may damage the constitution and facilitate the manifestations of severe mental illnesses. This was the first clear association between a well-defined measurable environmental factor and the causation of schizophrenia.
In a fine series of studies in which he proved beyond doubt the mutability of disease, Hare displayed his mastery of deductive skills. His data showed that there had been a natural decline in deaths from dementia paralytica from 1901 to 1957. This disease is due to syphilitic infection of the brain and became treatable with penicillin in 1945, but he demonstrated that the decline in its prevalence could not be attributed to improvements in medical treatment. He ingeniously postulated a gradual reduction in the virulence of the syphilitic organism in the absence of direct laboratory proof.
Further research into the changes of mental illness over historical time produced startling findings. Patients admitted to the 19th-century mental asylums with acute attacks of "insanity" were noted to suffer from high mortality rates, and those who survived often underwent profound deterioration (at that time called "dementia"). During the 20th century, and more so during recent decades, the prognosis of serious mental illnesses has improved. Hare argued that this improvement had begun well before the introduction of progressive forms of care and modern pharmacotherapy. He concluded that diseases change with time and that psychiatric diseases change more quickly than others because the expression is largely psychological and follows changing fashions in the mode of expressing mental distress.
The culmination of Hare's historical research was revealed in his 1982 Maudsley lecture in which he marshalled the evidence that there had been an epidemic of "insanity" during the second half of the 19th century, and probably during the first half as well. This is what led to a growing demand for asylum accommodation and a constant need to build new asylums between 1840 and 1920. He argued cogently that this increase in mental illness was principally due to a rise in dementia praecox, now known as schizophrenia. He concluded that purely genetic explanations for schizophrenia were insufficient and it was necessary to examine also specific environmental factors of a physical kind which had yet to be found. Among these he favoured an infective cause.
Hitherto, Hare's contributions to our understanding of mental illness have been insufficiently recognised. His work was that of a builder who concentrated on laying sure foundations on which others could build further. Psychiatrists who are aware of his evidence pointing to an infective cause for schizophrenia have in recent years channelled their energies into this field of research. Others who understand his concept of the mutability of disease have been emboldened to describe new forms of mental illness and rewrite clinical descriptions which have become outdated.
On the whole, Hare preferred to study groups of patients rather than individuals. An exception was his subjective observations on his attacks of migraine. They were preceded by premonitory symptoms consisting of flashes of light moving from the centre to the periphery of his field of vision. He recorded this march of events by the simple means of a ruler and a sheet of white paper on which he projected the spreading semicircle of flashing lights. The consistent pattern and duration of this disturbance led him to conclude that there had been an interference with a basic physiological process in his brain.
Anyone who knew Edward Hare appreciated that he was a man of singular modesty. He acknowledged that as a young psychiatrist he had little ambition but he was encouraged to change when Professor Aubrey Lewis urged him to join the staff of the Maudsley. He shared with this mentor the quality of scepticism which he defended as merely the wish to look more closely.
During the last 25 years of his life, including his most scientifically productive years, he enjoyed the unfailing support of his wife, Fiby. Without her help he would have been unable to present his research findings in Vancouver (1990) and Japan (1993). He is survived by her and by his daughter Anne from a previous marriage .
Edward Henry Hare, psychiatrist: born Stoke-on-Trent 21 August 1917; consultant, Bethlem Royal and Maudsley Hospital 1957-82; FRCPsych 1971, FRCP 1973; Editor, British Journal of Psychiatry 1972-77; married 1945 Margaret Myddelton (died 1962; one daughter), 1971 Fiby Gabbay; died London 8 December 1996.