title: Quantity and quality of psychotherapy trials for depression in the past five decades.
abstract: BACKGROUND
  Over the years randomized controlled trials (RCTs) of various psychotherapies for treating depression have provided evidence to demonstrate the interventions' efficacy/effectiveness. However, recent researches suggest that the quality of some RCTs were actually less than ideal, which could hence have biased their results. The present study aims to assess (1) the changes in characteristics of RCTs of psychotherapies for treating adult depression; (2) the temporal changes in their trial quality, and (3) the quality differences among different therapeutic approaches.
  
  
  METHODS
  We included 135 RCTs of psychotherapies treating adult depression published from year 1969 to 2011. Temporal changes in trials' characteristics including their quantity and quality were assessed at study-level and arm-level. Quality differences among different schools of psychotherapy were assessed at arm-level.
  
  
  RESULTS
  Changes in quantity and improvements in methodological quality were found at study-level. Positive changes in trial quality at arm-level were observed in most aspects. Comparisons made across different schools of psychotherapy revealed statistically significant differences among them, with earlier behavior therapy trials doing worst and more recent third wave cognitive-behavior therapy doing best.
  
  
  CONCLUSIONS
  We could not determine whether the observed changes in quality resulted from actual improvement in trial quality and/or from improved reporting. The relatively smaller number of arms for several types of interventions could weaken the representativeness when making comparisons across psychotherapeutic approaches.
  
  
  CONCLUSIONS
  Our study revealed positive temporal changes in both trial quantity and quality over the past five decades and has also spotted possible areas for further improvement.
authors.affiliation: Kyoto University Graduate School of Medicine/School of Public Health, Kyoto, Japan.
authors.forename: Peiyao
authors.initials: P
authors.lastname: Chen
authors.affiliation: Departments of Health Promotion and Human Behavior and of Clinical Epidemiology, Kyoto University Graduate School of Medicine/School of Public Health, Yoshida Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan. Electronic address: furukawa@kuhp.kyoto-u.ac.jp.
authors.forename: Toshiaki A
authors.initials: TA
authors.lastname: Furukawa
authors.affiliation: Kyoto University Graduate School of Medicine/School of Public Health, Kyoto, Japan.
authors.forename: Kiyomi
authors.initials: K
authors.lastname: Shinohara
authors.affiliation: Kyoto University Graduate School of Medicine/School of Public Health, Kyoto, Japan.
authors.forename: Mina
authors.initials: M
authors.lastname: Honyashiki
authors.affiliation: Kyoto University Graduate School of Medicine/School of Public Health, Kyoto, Japan.
authors.forename: Hissei
authors.initials: H
authors.lastname: Imai
authors.affiliation: Kyoto University Graduate School of Medicine/School of Public Health, Kyoto, Japan.
authors.forename: Kayoko
authors.initials: K
authors.lastname: Ichikawa
authors.affiliation: School of Social and Community Medicine, University of Bristol, Bristol, UK.
authors.forename: Deborah M
authors.initials: DM
authors.lastname: Caldwell
authors.affiliation: Centre for Academic Mental Health, School of Social and Community Medicine, University of Bristol, Bristol, UK.
authors.forename: Vivien
authors.initials: V
authors.lastname: Hunot
authors.affiliation: Centre for Academic Mental Health, School of Social and Community Medicine, University of Bristol, Bristol, UK.
authors.forename: Rachel
authors.initials: R
authors.lastname: Churchill
mesh_terms: D000328:Adult; D003866:Depressive Disorder / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D011613:Psychotherapy / Q000379:methods*; D016032:Randomized Controlled Trials as Topic / Q000592:standards*
keywords: Depressive disorder; Psychotherapies; Randomized controlled trials