• concept of health
• concept of mental health
• ethics
• philosophy of medicine
• philosophy of the health professions

In ‘Rethinking Disease’, Powell and Scarffe1 propose what in effect is a modification of Jerome Wakefield’s2 3 harmful dysfunction analysis (HDA) of medical (including mental) disorder. The HDA maintains that ‘disorder’ (or ‘disease’ in Powell and Scarffe’s terminology) is a hybrid factual and value concept requiring that a biological dysfunction, understood as a failure of some feature to perform a naturally selected function, causes harm to the individual as evaluated by social values. Powell and Scarffe accept both the HDA’s evolutionary biological function component and its incorporation of a value component. Their proposed ‘new twist’ is to revise the value component: ‘Our proposed definition of disease is as follows: a biomedical state is a disease only if it implicates a biological dysfunction that is, or would be, properly disvalued’. So, they propose that a disorder is a ‘properly disvalued dysfunction’ rather than a ‘harmful dysfunction’, an approach they term ‘thickly normative’ in contrast to the thin normative approach of the HDA. 

There has been a surge of interest recently in better understanding the ‘harm’ component of the HDA. Powell and Scarffe’s analysis is a helpful contribution to this discussion. We focus here exclusively on their proposal regarding the analysis of the concept of disorder and ignore many important related issues that the authors address, ranging from prioritising resource allocation between disorders and non-disorders to whether the concept of disorder should be replaced by a generic welfarist concept. The resolution of these additional issues depends on first understanding ‘disorder’. The authors’ proposed changes to the HDA also deserve evaluation because the HDA, which has been endorsed by leading nosologists,4 plays an influential role in nosological debate across categories of disorder ranging, for example, from sexual paraphilias5 to psychopathy.6

A basic problem is that Powell and Scarffe misinterpret …