Background The history of obsessive compulsive, phobic and psychopathic behaviour can be traced to the 17th century AD.

Methods and results We draw attention to these behaviours in a Babylonian cuneiform medical text known as Shurpu. These three categories were united in the Babylonian mind around the concept of the māmīt ‘oath’ idea, the behaviour habits being so unbreakable it appeared that the subject had sworn an oath to do or not to do the action involved. The behavioural accounts were entirely objective, including what we would call immature, antisocial and criminal behaviour, and obsessional categories of contamination, aggression, orderliness of objects, sex and religion. They do not include subjective descriptions of obsessional thoughts, ruminations or the subject's attitude to their own behaviour, which are more modern fields of enquiry.

Conclusions The Babylonians had no understanding of brain or psychological function but they were remarkable describers of medical disease and behaviour. Although they had both physical and supernatural theories of many medical disorders and behaviours, they had an open mind on these particular behaviours which they regarded as a ‘mystery’ yet to be ‘resolved’. We are not aware of comparable accounts of these behaviours in ancient Egyptian or classical medicine. These Babylonian descriptions extend the history of these disorders to the first half of the second millennium BC.