The philosopher Plato, in the 4th century BC, distinguished natural madness, resulting from physical disease, from that given by divine gift. He insisted that mental disturbance should be treated within the family, which led to special temples being set aside as retreats for the mentally ill.

Hippocrates, a Greek physician writing at the same time (often considered to be the father of modern medicine), described five forms of madness (hysteria, epilepsy, acute mental disturbance with and without fever, and chronic mental disturbance), all of which he considered to be medical in origin and treatable by procedures such as emetics, bleeding, purges and dietary change. These procedures were aiming to reduce the excess of bodily fluids, or humours, which Hippocrates thought were responsible for mental disorder. An excess of black bile was thought to lead to depression (melancholy); an excess of yellow bile to irritability and anxiety (choleric); an excess of phlegm to indifference (phlegmatic); and an excess of blood to mood shifts (sanguinity). Thus some of the modern categories of disorder had clearly been identified even then.

The Greek physician Galen, in the 1st/2nd century AD, studied anatomy in his search for explanations, but is often considered to be the first person to suggest that abnormal behaviour could also have psychological origins (Halgin & Whitbourne 1993).

By the Middle Ages (500-1500) the demonological view had taken over in Europe, and madness again became linked with possession by evil spirits. This represented a reversion to earlier ideas about evil spirits, but the ideas had been embedded in the context of Christianity. Such individuals were more likely to be subjected to exorcism or burnt at the stake than treated medically. The Inquisition was an institution set up by the Roman Catholic Church to discover and suppress heretics (those people who held opinions opposed to those of the church). In 1484, the Inquisition began in earnest with the publication of the Malleus Malleficorum, the witchhunter's guide to diagnosing witches. This was one of the first books to be printed and widely circulated. According to Spanos (1978) as many as 100,000 persons were dealt with in this way between 1450-1600. Not all were mentally disordered of course (many were eliminated as the result of political or economic rivalry), but it is likely that many would have been.

However, at about the same time there was also the first attempt to provide secure places for mentally disordered persons. Until this time lunatics (as they were generally known) had either been accommodated by their own families or simply cast out to fend for themselves. Bethlem hospital, opened to lunatics in London in 1403, was the first in Europe, and it was followed by another in Spain in 1408, in North America in 1639 and France in 1657.

These two views of madness, as disease or as demonic possession, continued to conflict for many centuries; only recently has the latter approach been replaced by a broader, 'moral' view of such behaviour that is less reliant on religion. . .