title: Is longer-term psychodynamic psychotherapy more effective than shorter-term therapies? Review and critique of the evidence.
abstract: BACKGROUND
  In 2008, Leichsenring and Rabung performed a meta-analysis of 8 studies of longer-term psychodynamic psychotherapy (LTPP). The work was published in the Journal of the American Medical Association (vol. 300, pp 1551-1565), and they concluded that LTPP was more effective than shorter-term therapies.
  
  
  METHODS
  Given that such claims have the potential to influence treatment decisions and policies, we re-examined the meta-analysis and the 8 studies.
  
  
  RESULTS
  We found a miscalculation of the effect sizes used to make key comparisons. Claims for the effectiveness of LTPP depended on a set of small, underpowered studies that were highly heterogeneous in terms of patients treated, interventions, comparison-control groups, and outcomes. LTPP was compared to 12 types of comparison-controls, including control groups that did not involve any psychotherapy, short-term psychodynamic psychotherapy, and unvalidated treatments. Additionally, the studies failed to protect against threats to bias, and had poor internal validity.
  
  
  CONCLUSIONS
  Overall, we found no evidence to support claims of superiority of LTPP over shorter-term methods of psychotherapy.
authors.affiliation: Faculty of Life and Social Sciences, Swinburne University of Technology, Hawthorn, Victoria, Australia. sbhar@swin.edu.au
authors.forename: Sunil S
authors.initials: SS
authors.lastname: Bhar
authors.forename: Brett D
authors.initials: BD
authors.lastname: Thombs
authors.forename: Monica
authors.initials: M
authors.lastname: Pignotti
authors.forename: Marielle
authors.initials: M
authors.lastname: Bassel
authors.forename: Lisa
authors.initials: L
authors.lastname: Jewett
authors.forename: James C
authors.initials: JC
authors.lastname: Coyne
authors.forename: Aaron T
authors.initials: AT
authors.lastname: Beck
mesh_terms: D006801:Humans; D001523:Mental Disorders / Q000628:therapy*; D011575:Psychoanalytic Therapy / Q000379:methods*; D015203:Reproducibility of Results; D018401:Sample Size; D013997:Time Factors; D016896:Treatment Outcome