title: Dissociative symptoms are associated with reduced neuropsychological performance in patients with recurrent depression and a history of trauma exposure.
abstract: BACKGROUND
  Although preliminary work suggests that dissociative symptoms may impact neuropsychological performance in trauma-exposed populations, the relation between dissociation and cognitive performance has not been explored in patients with depression.
  
  
  OBJECTIVE
  The present study examined dissociative symptoms in relation to neuropsychological performance in participants with a primary diagnosis of recurrent major depressive disorder (MDD) and a history of trauma exposure.
  
  
  METHODS
  Twenty-three participants with MDD and 20 healthy controls who did not differ in age, sex, education, or IQ were assessed. In addition to a standardized neuropsychological battery assessing frontotemporally mediated cognitive processes, participants completed clinical measures assessing dissociative symptoms, illness severity, and past history of trauma exposure.
  
  
  RESULTS
  Among participants with MDD, greater severity of derealization was associated with reduced performance on measures of delayed visuospatial recall and recognition on a task of verbal memory recognition. In addition, more severe depersonalization was associated with slower processing speed and a response style lending itself toward better performance in a less active environment.
  
  
  CONCLUSIONS
  These findings point toward dissociative symptoms as a transdiagnostic factor associated with neuropsychological dysfunction in patients with depression and a history of trauma. Limitations and recommendations for future research are discussed.
authors.affiliation: Department of Psychiatry and Behavioral Neurosciences, McMaster University, Hamilton, Canada.|Mood Disorders Research Unit, St. Joseph's Healthcare, Hamilton, Canada.
authors.forename: Melissa
authors.initials: M
authors.lastname: Parlar
authors.affiliation: Department of Psychiatry, University of Western Ontario, London, Canada.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Frewen
authors.affiliation: Department of Psychiatry and Behavioral Neurosciences, McMaster University, Hamilton, Canada.|Mood Disorders Research Unit, St. Joseph's Healthcare, Hamilton, Canada.
authors.forename: Carolina
authors.initials: C
authors.lastname: Oremus
authors.affiliation: Department of Psychiatry, University of Western Ontario, London, Canada.
authors.forename: Ruth A
authors.initials: RA
authors.lastname: Lanius
authors.affiliation: Department of Psychiatry and Behavioral Neurosciences, McMaster University, Hamilton, Canada.|Mood Disorders Research Unit, St. Joseph's Healthcare, Hamilton, Canada.|Homewood Research Institute, Guelph, Canada; mmckinno@stjosham.on.ca.
authors.forename: Margaret C
authors.initials: MC
authors.lastname: McKinnon
keywords: cognition; depression; dissociation; transdiagnostic; traumatic stress