title: Effects of electroconvulsive therapy on cognitive functioning in patients with depression: protocol for a systematic review and meta-analysis.
abstract: BACKGROUND
  Depression is the leading cause of disability worldwide, affecting approximately 350 million people. Evidence indicates that only 60-70% of persons with major depressive disorder who tolerate antidepressants respond to first-line drug treatment; the remainder become treatment resistant. Electroconvulsive therapy (ECT) is considered an effective therapy in persons with treatment-resistant depression. The use of ECT is controversial due to concerns about temporary cognitive impairment in the acute post-treatment period. We will conduct a meta-analysis to examine the effects of ECT on cognition in persons with depression.
  
  
  METHODS
  This systematic review and meta-analysis has been registered with PROSPERO (registration number: CRD42014009100). We developed our methods following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. We are searching MEDLINE, PsychINFO, EMBASE, CINAHL and Cochrane from the date of database inception to the end of October 2014. We are also searching the reference lists of published reviews and evidence reports for additional citations. Comparative studies (randomised controlled trials, cohort and case-control) published in English will be included in the meta-analysis. Three clinical neuropsychologists will group the cognitive tests in each included article into a set of mutually exclusive cognitive subdomains. The risk of bias of randomised controlled trials will be assessed using the Jadad scale. We will supplement the Jadad scale with additional questions based on the Cochrane risk of bias tool. The risk of bias of cohort and case-control studies will be assessed using the Newcastle-Ottawa Scale. We will employ the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) to assess the strength of evidence.
  
  
  METHODS
  Separate meta-analyses will be conducted for each ECT treatment modality and cognitive subdomain using Comprehensive Meta-Analysis V.2.0.
authors.affiliation: McMaster Integrative Neuroscience Discovery and Study (MINDS) & Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Carolina
authors.initials: C
authors.lastname: Oremus
authors.affiliation: School of Public Health and Health Systems, University of Waterloo, Waterloo, Ontario, Canada.
authors.forename: Mark
authors.identifier: http://orcid.org/0000-0001-6542-5438
authors.initials: M
authors.lastname: Oremus
authors.affiliation: Clinical Neuropsychology Service & Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Heather
authors.initials: H
authors.lastname: McNeely
authors.affiliation: Clinical Neuropsychology Service & Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Bruno
authors.initials: B
authors.lastname: Losier
authors.affiliation: McMaster Integrative Neuroscience Discovery and Study (MINDS) & Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Melissa
authors.initials: M
authors.lastname: Parlar
authors.affiliation: Department of Psychology, Ryerson University, Toronto, Ontario, Canada.
authors.forename: Matthew
authors.initials: M
authors.lastname: King
authors.affiliation: Mood Disorders Program & Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Gary
authors.initials: G
authors.lastname: Hasey
authors.affiliation: Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Gagan
authors.initials: G
authors.lastname: Fervaha
authors.affiliation: Bloorview Research Institute, Holland Bloorview Kids Rehabilitation Hospital, Toronto, Ontario, Canada.
authors.forename: Allyson C
authors.initials: AC
authors.lastname: Graham
authors.affiliation: Faculty of Medicine, Undergraduate Medical Education, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Caitlin
authors.initials: C
authors.lastname: Gregory
authors.affiliation: McMaster Integrative Neuroscience Discovery and Study (MINDS), McMaster University, Hamilton, Ontario, Canada.
authors.forename: Lindsay
authors.initials: L
authors.lastname: Hanford
authors.affiliation: McMaster Integrative Neuroscience Discovery and Study (MINDS) & Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Anthony
authors.initials: A
authors.lastname: Nazarov
authors.affiliation: McMaster Integrative Neuroscience Discovery and Study (MINDS) & Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Maria
authors.initials: M
authors.lastname: Restivo
authors.affiliation: McMaster Integrative Neuroscience Discovery and Study (MINDS), McMaster University, Hamilton, Ontario, Canada.
authors.forename: Erica
authors.initials: E
authors.lastname: Tatham
authors.affiliation: Department of Psychology, University of Calgary, Calgary, Ontario, Canada.
authors.forename: Wanda
authors.initials: W
authors.lastname: Truong
authors.affiliation: Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Geoffrey B C
authors.initials: GB
authors.lastname: Hall
authors.affiliation: Department of Psychiatry, University of Western Ontario, London, Ontario, Canada.
authors.forename: Ruth
authors.initials: R
authors.lastname: Lanius
authors.affiliation: Mood Disorders Program, St. Joseph's Healthcare Hamilton, Homewood Research Institute, & Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Margaret
authors.initials: M
authors.lastname: McKinnon
mesh_terms: D003071:Cognition; D003072:Cognition Disorders / Q000209:etiology*; D003865:Major Depressive Disorder / Q000628:therapy*; D061218:Depressive Disorder, Treatment-Resistant / Q000628:therapy*; D004565:Electroconvulsive Therapy / Q000009:adverse effects* / Q000379:methods; D006801:Humans; D012107:Research Design; D000078202:Systematic Reviews as Topic; D015201:Meta-Analysis as Topic