A Radical But Flawed Proposal: Comments on Rehm et al. ‘Defining Substance Use Disorders: Do We Really Need More than Heavy Use?’

  1. Nick Heather*
  1. Department of Psychology, Northumbria University, Newcastle upon Tyne, UK
  1. *Corresponding author: Department of Psychology, Faculty of Health & Life Sciences, Northumberland Building, Northumbria University, Newcastle upon Tyne NE1 8ST, UK. Tel: +44-191-227-4521; Fax: +44-191-227-3190; E-mail: nick.heather{at}northumbria.ac.uk

Rehm et al. (2013) have given us a provocative proposal for revising the definition of substance use disorders, with radical implications for treatment, prevention and policy. They argue that, for the purposes of reducing substance-related harm, concepts of dependence and addiction are superfluous in this definition and that all we need is the concept of ‘heavy use over time’. This proposal will no doubt generate a lively and interesting debate and is to be commended for that reason. However, I believe it to be founded on deeply flawed reasoning and a short-sighted view of its topic. Owing to the prominence of its authors, their article may well be influential in the field of substance use disorders but it will be most regrettable, in my view, if it leads to the kind of changes they advocate.

The underlying mistake in their argument is to identify the concepts of dependence and addiction with definitions in the International Classification of Diseases and the Diagnostic and Statistical Manual of Mental Disorders. (There may be differences between the terms ‘dependence’ and ‘addiction’ but for present purposes I see no advantages in using the former and will therefore confine myself to the latter in this commentary. I will also illustrate my own argument, where appropriate, by the example of alcohol use rather than substance use in general.) These definitions were developed mainly for bureaucratic purposes and, as the authors themselves recognize, to respond to socio-political influences on diagnostic practice; this tick-box approach to definition does not help us to think clearly about what addiction means and what part it plays in the production of substance-related harm. If these were the only or the most useful definitions of addiction available, some of the claimed benefits for switching to heavy use over time may be justified. But …