title: Untreated short-term course of major depression: a meta-analysis of outcomes from studies using wait-list control groups.
abstract: BACKGROUND
  While the short-term response rates to antidepressant medication and placebo are well established, very little is known about the short-term course of untreated depression. Knowledge of the course of untreated depression can serve as a benchmark for assessing the true benefits of active treatment.
  
  
  METHODS
  A meta-analysis was performed analyzing the outcomes of all psychotherapy studies that randomized adult outpatients with major depressive disorder to a wait-list control group.
  
  
  RESULTS
  Nineteen studies involving 221 subjects were reviewed. The mean decrease in Hamilton Rating Scale for Depression scores over 2-20 weeks was 11.9%, while the mean decrease in Beck Depression Inventory scores was 15.7%. Using a subsample of studies that reported individual outcomes, we estimated that 15 of 76 subjects (19.7%) improved to a degree comparable to what would be considered a positive response in antidepressant trials.
  
  
  CONCLUSIONS
  In the short-term, depressive symptomatology can be expected to decrease by about 10-15% on average without treatment. As many as 20% of subjects who participate in a short-term antidepressant trial may experience a spontaneous remission.
authors.affiliation: Department of Psychiatry and Human Behavior, Brown University School of Medicine, Rhode Island Hospital, 235 Plain St., Suite 501, Providence, RI 02905, USA. mposternak@lifespan.org
authors.forename: M A
authors.initials: MA
authors.lastname: Posternak
authors.forename: I
authors.initials: I
authors.lastname: Miller
mesh_terms: D000328:Adult; D019985:Benchmarking; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000523:psychology / Q000628:therapy*; D005500:Follow-Up Studies; D006801:Humans; D011614:Psychotherapy, Brief; D016032:Randomized Controlled Trials as Topic; D016896:Treatment Outcome; D014850:Waiting Lists