title: The function of 'functional': a mixed methods investigation.
abstract: OBJECTIVE
  The term 'functional' has a distinguished history, embodying a number of physiological concepts, but has increasingly come to mean 'hysterical'. The DSM-V working group proposes to use 'functional' as the official diagnostic term for medically unexplained neurological symptoms (currently known as 'conversion disorder'). This study aimed to explore the current neurological meanings of the term and to understand its resilience.
  
  
  METHODS
  Mixed methods were used, first interviewing the neurologists in a large UK region and then surveying all neurologists in the UK on their use of the term.
  
  
  RESULTS
  The interviews revealed four dominant uses--'not organic', a physical disability, a brain disorder and a psychiatric problem--as well as considerable ambiguity. Although there was much dissatisfaction with the term, the ambiguity was also seen as useful when engaging with patients. The survey confirmed these findings, with a majority adhering to a strict interpretation of 'functional' to mean only 'not organic', but a minority employing it to mean different things in different contexts - and endorsing the view that 'functional' would one day be a neurological construct again.
  
  
  CONCLUSIONS
  'Functional' embodies real divisions in neurologists' conceptualisation of unexplained symptoms and, perhaps, between those of patients and neurologists: its diversity of meanings allows it to be a common term while meaning different things to different people, or at different times, and thus conceal some of the conflict in a particularly contentious area. This flexibility may help explain the term's longevity.
authors.affiliation: King’s College London, Department of Psychological Medicine, Institute of Psychiatry, Weston Education Centre, London, UK. richard.kanaan@kcl.ac.uk
authors.forename: Richard A
authors.initials: RA
authors.lastname: Kanaan
authors.forename: David
authors.initials: D
authors.lastname: Armstrong
authors.forename: Simon C
authors.initials: SC
authors.lastname: Wessely
mesh_terms: D001921:Brain / Q000503:physiopathology; D003291:Conversion Disorder / Q000503:physiopathology; D039721:Diagnostic and Statistical Manual of Mental Disorders; D006801:Humans; D007407:Interviews as Topic; D009462:Neurology; D009626:Terminology as Topic; D006113:United Kingdom