The late 1950s was a time of rapid progress in the treatment of psychiatric disorder, liberal legislation in mental health and expansion of research into the causes of mental illness along a broad front. Drugs that were effective in treating depressive illness had been recently discovered and their applications in clinical practice spread with an unprecedented rapidity. The Percy Commission was coming to the end of its deliberations, and the English Mental Health Act of 1959 which followed has been widely described as this century's most humane piece of legislation in relation to the mentally ill to be placed on the statute books anywhere. The prospects for better mutual understanding between the law and psychiatry were full of high promise.

The changes that followed the creation of more stimulating and active regimes in psychiatric wards and the successes of new treatments for depression, schizophrenia and other disorders generated a fresh upsurge of scientific investigation into the biological and social origins of mental illness. The steep decline in the number of beds in English mental hospitals which began in 1954 intensified the atmosphere of optimism. There had been 344 beds per 100000 population at the end of 1954. This was halved to 171 per 100000 by 1978. The total number of mental hospital beds in England was reduced from 160000 to 80000 in the same period. The reduction was due in part to the discharge of patients who had been resident in mental hospitals for many years, but to a greater extent to a decrease in the average length of stay of patients. This was the beginning of the era of the revolving door.