title: Efficacy of Self-guided Internet-Based Cognitive Behavioral Therapy in the Treatment of Depressive Symptoms: A Meta-analysis of Individual Participant Data.
abstract: OBJECTIVE
  Self-guided internet-based cognitive behavioral therapy (iCBT) has the potential to increase access and availability of evidence-based therapy and reduce the cost of depression treatment.
  
  
  OBJECTIVE
  To estimate the effect of self-guided iCBT in treating adults with depressive symptoms compared with controls and evaluate the moderating effects of treatment outcome and response.
  
  
  METHODS
  A total of 13 384 abstracts were retrieved through a systematic literature search in PubMed, Embase, PsycINFO, and Cochrane Library from database inception to January 1, 2016.
  
  
  METHODS
  Randomized clinical trials in which self-guided iCBT was compared with a control (usual care, waiting list, or attention control) in individuals with symptoms of depression.
  
  
  METHODS
  Primary authors provided individual participant data from 3876 participants from 13 of 16 eligible studies. Missing data were handled using multiple imputations. Mixed-effects models with participants nested within studies were used to examine treatment outcomes and moderators.
  
  
  METHODS
  Outcomes included the Beck Depression Inventory, Center for Epidemiological Studies-Depression Scale, and 9-item Patient Health Questionnaire scores. Scales were standardized across the pool of the included studies.
  
  
  RESULTS
  Of the 3876 study participants, the mean (SD) age was 42.0 (11.7) years, 2531 (66.0%) of 3832 were female, 1368 (53.1%) of 2574 completed secondary education, and 2262 (71.9%) of 3146 were employed. Self-guided iCBT was significantly more effective than controls on depressive symptoms severity (β = -0.21; Hedges g  = 0.27) and treatment response (β = 0.53; odds ratio, 1.95; 95% CI, 1.52-2.50; number needed to treat, 8). Adherence to treatment was associated with lower depressive symptoms (β = -0.19; P = .001) and greater response to treatment (β = 0.90; P < .001). None of the examined participant and study-level variables moderated treatment outcomes.
  
  
  CONCLUSIONS
  Self-guided iCBT is effective in treating depressive symptoms. The use of meta-analyses of individual participant data provides substantial evidence for clinical and policy decision making because self-guided iCBT can be considered as an evidence-based first-step approach in treating symptoms of depression. Several limitations of the iCBT should be addressed before it can be disseminated into routine care.
authors.affiliation: Department of Clinical Psychology and EMGO Institute for Health and Care Research, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands.
authors.forename: Eirini
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authors.lastname: Karyotaki
authors.affiliation: Department of Clinical Psychology and EMGO Institute for Health and Care Research, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands.
authors.forename: Heleen
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authors.lastname: Riper
authors.affiliation: Department of Epidemiology and Biostatistics and EMGO Institute for Health and Care Research, Vrije Universiteit University Amsterdam, Amsterdam, the Netherlands.
authors.forename: Jos
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authors.lastname: Twisk
authors.affiliation: Department of Psychiatry, Geestelijke Gezondheidszorg inGeest inGeest and Vrije Universiteit University Medical Centre, Amsterdam, the Netherlands4EMGO Institute for Health and Care Research, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands.
authors.forename: Adriaan
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authors.lastname: Hoogendoorn
authors.affiliation: Department of Clinical Psychology and EMGO Institute for Health and Care Research, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands.
authors.forename: Annet
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authors.affiliation: Department of Psychology and Technology, Jaume University, Castellon, Spain.
authors.forename: Adriana
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authors.affiliation: Black Dog Institute and University of New South Wales, Prince of Wales Hospital, Sydney, Australia7Center for Mental Health, University of Melbourne, Melbourne, Australia.
authors.forename: Andrew
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authors.affiliation: Research Department, Gaia AG, Hamburg, Germany9Department of Psychology, City University, London, England.
authors.forename: Björn
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authors.affiliation: Department of Psychology and Technology, Jaume University, Castellon, Spain10IBER of Physiopathology of Obesity and Nutrition, Santiago de Compostela, Spain.
authors.forename: Cristina
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authors.lastname: Botella
authors.affiliation: Department of Health Sciences, University of York, York, England.
authors.forename: Elizabeth
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authors.affiliation: Department of Behavioural Sciences and Learning, Sweden Institute for Disability Research, Linköping University, Linköping, Sweden13Department of Clinical Neuroscience, Psychiatry Section, Karolinska Institute for Disability Research, Stockholm, Sweden.
authors.forename: Gerhard
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authors.affiliation: Black Dog Institute and University of New South Wales, Prince of Wales Hospital, Sydney, Australia.
authors.forename: Helen
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authors.affiliation: Department of Psychiatry and Psychotherapy, Luebeck University, Luebeck, Germany.
authors.forename: Jan P
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authors.affiliation: Department of Psychiatry and Psychotherapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Johanna
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authors.lastname: Schröder
authors.affiliation: Department of Psychology and Technology, Jaume University, Castellon, Spain10IBER of Physiopathology of Obesity and Nutrition, Santiago de Compostela, Spain.
authors.forename: Juana
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authors.affiliation: Institute of Mental Health, University of Nottingham, Nottingham, England.
authors.forename: Justine
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authors.affiliation: Research School of Psychology, College of Biology, Medicine & Environment, Australian National University, Canberra, Australia.
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authors.lastname: Griffiths
authors.affiliation: Centre for Mental Health Research, The Australian National University, Canberra, Australia.
authors.forename: Louise
authors.initials: L
authors.lastname: Farrer
authors.affiliation: Department of Clinical Psychology and EMGO Institute for Health and Care Research, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands.
authors.forename: Marcus J H
authors.initials: MJ
authors.lastname: Huibers
authors.affiliation: Department of Primary Care and Public Health Sciences, King's College London, London, England.
authors.forename: Rachel
authors.initials: R
authors.lastname: Phillips
authors.affiliation: Department of Health Sciences, University of York, York, England.
authors.forename: Simon
authors.initials: S
authors.lastname: Gilbody
authors.affiliation: Department of Psychiatry and Psychotherapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Moritz
authors.affiliation: Department of Clinical Psychology and Psychotherapy, University of Bern, Bern, Switzerland.
authors.forename: Thomas
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authors.lastname: Berger
authors.affiliation: Department of Psychology and Health, Tilburg University and Diagnostic Centre Eindhoven, Eindhoven, the Netherlands.
authors.forename: Victor
authors.initials: V
authors.lastname: Pop
authors.affiliation: Department of Psychology and Health, Tilburg University and Diagnostic Centre Eindhoven, Eindhoven, the Netherlands.
authors.forename: Viola
authors.initials: V
authors.lastname: Spek
authors.affiliation: Department of Clinical Psychology and EMGO Institute for Health and Care Research, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands2Department of Epidemiology and Biostatistics and EMGO Institute for Health and Care Research, Vrije Universiteit University Amsterdam, Amsterdam, the Netherlands.
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mesh_terms: D000328:Adult; D015928:Cognitive Behavioral Therapy / Q000379:methods*; D003866:Depressive Disorder / Q000175:diagnosis / Q000523:psychology / Q000628:therapy*; D005260:Female; D006801:Humans; D020407:Internet; D008297:Male; D016032:Randomized Controlled Trials as Topic; D013813:Therapy, Computer-Assisted / Q000379:methods*; D016896:Treatment Outcome