what kind of image does the term ‘drug user’ generally bring to mind in today's society? Is the average response to a statement that someone is ‘taking drugs’ likely to be an inquiry about what type of illness he or she is suffering from and what medication is being used to treat it? Probably not, because for most people ‘taking drugs’ tends to have a connotation that links it with abuse rather than with medicinal use.

Yet the word ‘drug’ was not always so closely linked in the public mind with substance abuse. The definition of the noun drug in volume III (published in 1897) of the original edition of the Oxford English Dictionary (OED) is as follows: ‘An original, simple medicinal substance, organic or inorganic, whether used by itself in its natural condition or prepared by art, or as an ingredient in a medicine or medicament.’

The OED went on to discuss other aspects of the history and use of the term that need not be considered here. From the point of view of this essay, the key fact to note is that the noun drug is associated with medicinal or related use. There is no reference to recreational use or abuse of a substance in the definition.