title: Multidimensional apathy in ALS: validation of the Dimensional Apathy Scale.
abstract: OBJECTIVE
  Apathy is a prominent symptom of amyotrophic lateral sclerosis (ALS), but measurement is confounded by physical disability. Furthermore, it has been traditionally measured as a unidimensional symptom despite research demonstrating a multifaceted construct. The new Dimensional Apathy Scale (DAS) has been specifically designed for patients with motor disability to measure 3 neurologically based subtypes of apathy: Executive, Emotional and Initiation. We aimed to explore this behavioural symptom by examining the substructure of apathy in ALS and to determine the reliability and validity of the DAS in patients and their carers.
  
  
  METHODS
  Patients and carers were recruited through the national Scottish Motor Neurone Disease Register and were asked to complete the DAS, the standardised Apathy Evaluation Scale, and the Geriatric Depression Scale-Short Form. 83 patients with ALS, 75 carers and 83 sex-matched, age-matched and education-matched controls participated.
  
  
  RESULTS
  When compared with healthy controls, patients showed a significant increase in apathy on the Initiation subscale, and were significantly less apathetic on the Emotional subscale. Scores on the DAS patient and carer versions did not significantly differ. Internal consistency reliability, convergent and discriminant validity were found to be good for the DAS subscales. There was no association between the DAS and functional disability using the ALS Functional Rating Scale.
  
  
  CONCLUSIONS
  Apathy in ALS is characterised by a specific profile of increased initiation apathy and reduced emotional apathy. The DAS is a reliable and valid measure for the assessment of multidimensional apathy in ALS.
authors.affiliation: Department of Psychology, School of Philosophy, Psychology & Language Sciences, University of Edinburgh, Edinburgh, UK Anne Rowling Regenerative Neurology Clinic, University of Edinburgh, Edinburgh, UK Alzheimer Scotland Dementia Research Centre, University of Edinburgh, Edinburgh, UK Euan MacDonald Centre for MND Research, University of Edinburgh, Edinburgh, UK.
authors.forename: Ratko
authors.initials: R
authors.lastname: Radakovic
authors.affiliation: Anne Rowling Regenerative Neurology Clinic, University of Edinburgh, Edinburgh, UK.
authors.forename: Laura
authors.initials: L
authors.lastname: Stephenson
authors.affiliation: Anne Rowling Regenerative Neurology Clinic, University of Edinburgh, Edinburgh, UK.
authors.forename: Shuna
authors.initials: S
authors.lastname: Colville
authors.affiliation: Euan MacDonald Centre for MND Research, University of Edinburgh, Edinburgh, UK Department of Neurology, Ninewells Hospital and Medical School, Dundee, UK.
authors.forename: Robert
authors.initials: R
authors.lastname: Swingler
authors.affiliation: Anne Rowling Regenerative Neurology Clinic, University of Edinburgh, Edinburgh, UK.
authors.forename: Siddharthan
authors.initials: S
authors.lastname: Chandran
authors.affiliation: Department of Psychology, School of Philosophy, Psychology & Language Sciences, University of Edinburgh, Edinburgh, UK Anne Rowling Regenerative Neurology Clinic, University of Edinburgh, Edinburgh, UK Euan MacDonald Centre for MND Research, University of Edinburgh, Edinburgh, UK.
authors.forename: Sharon
authors.initials: S
authors.lastname: Abrahams
mesh_terms: D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000175:diagnosis* / Q000523:psychology*; D057565:Apathy; D017028:Caregivers / Q000523:psychology; D003866:Depressive Disorder / Q000175:diagnosis / Q000523:psychology; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data*; D011594:Psychometrics / Q000706:statistics & numerical data; D012016:Reference Values; D015203:Reproducibility of Results