title: Effort-based decision making as an objective paradigm for the assessment of motivational deficits in schizophrenia.
abstract: BACKGROUND
  Negative symptoms and motivational deficits are prevalent features of schizophrenia, and represent robust predictors of real-world functional outcomes. The standard for assessment of these symptoms is clinical interview and severity ratings on standardized rating scales. In the present study we examined the psychometric properties of a performance-based measure of motivational deficits in patients with schizophrenia.
  
  
  METHODS
  Ninety-seven patients with schizophrenia were included in this investigation. Patients' willingness to expend effort for reward (i.e., motivation) was evaluated using an effort-based decision making paradigm where participants chose over a series of trials whether to expend a greater amount of effort for a larger monetary reward versus less effort for a smaller reward. Effort performance was evaluated twice, separated by a two-week interval.
  
  
  RESULTS
  Patients with schizophrenia opted to expend greater effort for trials with higher reward value and greater likelihood of reward receipt. Patients did not find the task overly difficult and reported being motivated to perform well, underscoring the tolerability of the task for patients. Test-retest consistency was good and there was only minimal change in scores over time. Effort performance was not related to sociodemographic or clinical variables (e.g., positive symptoms); however, deficit syndrome patients exerted effort for reward at a significantly lower rate than nondeficit patients.
  
  
  CONCLUSIONS
  The effort-based decision making task used in the present study represents an objective paradigm that can be used to evaluate motivational impairments in patients with schizophrenia. Such performance-based measures of motivation may also serve as viable endpoints in clinical trials.
authors.affiliation: Schizophrenia Division and Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Canada; Institute of Medical Science, University of Toronto, Toronto, Canada. Electronic address: gagan.fervaha@utoronto.ca.
authors.forename: Gagan
authors.initials: G
authors.lastname: Fervaha
authors.affiliation: Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Canada.
authors.forename: Mark
authors.initials: M
authors.lastname: Duncan
authors.affiliation: Schizophrenia Division and Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Canada; Institute of Medical Science, University of Toronto, Toronto, Canada; Department of Psychiatry, University of Toronto, Toronto, Canada.
authors.forename: George
authors.initials: G
authors.lastname: Foussias
authors.affiliation: Schizophrenia Division and Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Canada; Institute of Medical Science, University of Toronto, Toronto, Canada; Department of Psychiatry, University of Toronto, Toronto, Canada.
authors.forename: Ofer
authors.initials: O
authors.lastname: Agid
authors.affiliation: Schizophrenia Division and Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Canada; Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Canada.
authors.forename: Guy E
authors.initials: GE
authors.lastname: Faulkner
authors.affiliation: Schizophrenia Division and Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Canada; Institute of Medical Science, University of Toronto, Toronto, Canada; Department of Psychiatry, University of Toronto, Toronto, Canada.
authors.forename: Gary
authors.initials: G
authors.lastname: Remington
mesh_terms: D000328:Adult; D003657:Decision Making; D005260:Female; D006801:Humans; D008297:Male; D009042:Motivation; D011569:Psychiatric Status Rating Scales; D011581:Psychological Tests; D011594:Psychometrics; D012201:Reward; D012559:Schizophrenia / Q000175:diagnosis*; D012565:Schizophrenic Psychology
keywords: Amotivation; Antipsychotics; Apathy; Effort cost; Negative symptoms; Neurocognition