title: Natural course and placebo response in short-term, placebo-controlled studies in major depression: a meta-analysis of published and non-published studies.
abstract: BACKGROUND
  This study was conducted to investigate the role of natural course of a major depressive episode in short-term, placebo-controlled studies.
  
  
  METHODS
  We analyzed for sustained response all placebo arms and tricyclic arms from all randomized three-arm studies that were conducted in patients with a major depressive episode and were submitted to the Medicine Evaluation Board (1979-1991). The Medicine Evaluation Board is the regulatory authority of the Netherlands. A responder was defined as a patient with at least 50% improvement on the Hamilton Depression Rating Scale as compared to baseline score. A study responder was defined as a patient meeting response criteria at endpoint (Last Observation Carried Forward). A sustained responder was defined as a patient who, after becoming responder, remained a responder until the end of the study.
  
  
  RESULTS
  The ITT population incorporated 1989 patients in the tricyclic arm and 2042 patients in the placebo arm. There was a statistically significant difference for study responders: 39.3% in the tricyclic treatment group and 27.9% in the placebo group (difference 11.4; CI (95%): 8.5% 14.3%). However, no significant differences in sustained response patterns were found, with the exception of a significantly higher sustained response rate for initial responders at week 4.
  
  
  CONCLUSIONS
  While efficacy of tricyclic antidepressants was confirmed in this meta-analysis, the sustained response patterns of active treatment and placebo did not differ substantially, suggesting that many of the patients included in the studies were close to, or at the end of, their episode.
authors.affiliation: Medicines Evaluation Board of The Netherlands, Den Haag. JG.Storosum@CBG-MEB.nl
authors.forename: J G
authors.initials: JG
authors.lastname: Storosum
authors.forename: A J
authors.initials: AJ
authors.lastname: Elferink
authors.forename: B J
authors.initials: BJ
authors.lastname: van Zwieten
authors.forename: W
authors.initials: W
authors.lastname: van den Brink
authors.forename: J
authors.initials: J
authors.lastname: Huyser
mesh_terms: D000929:Antidepressive Agents, Tricyclic / Q000627:therapeutic use*; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000188:drug therapy* / Q000523:psychology; D006801:Humans; D010352:Patient Dropouts / Q000706:statistics & numerical data; D015990:Placebo Effect; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data*; D016896:Treatment Outcome
chemical_list: D000929:Antidepressive Agents, Tricyclic