title: Why prudence is needed when interpreting articles reporting clinical trial results in mental health.
abstract: Clinical trial results' reliability is impacted by reporting bias. This is primarily manifested as publication bias and outcome reporting bias.
  
  
  
  Mental health trials are prone to two methodological deficiencies: (1) using small numbers of participants that facilitates false positive findings and exaggerated size effects, and (2) the obligatory use of psychometric scales that require subjective assessments. These two deficiencies contribute to the publication of unreliable results. Considerable reporting bias has been found in safety and efficacy findings in psychotherapy and pharmacotherapy trials. Reporting bias can be carried forward to meta-analyses, a key source for clinical practice guidelines. The final result is the frequent overestimation of treatment effects that could impact patients and clinician-informed decisions.
  
  
  
  Prospective registration of trials and publication of results are the two major methods to reduce reporting bias. Prospective trial registration will allow checking whether they are published (so it will help to prevent publication bias) and, if published, whether those outcomes and analyses that were deemed as appropriate before trial commencement are actually published (hence helping to find out selective reporting of outcomes). Unfortunately, the rate of registered trials in mental health interventions is low and, frequently, of poor quality.
  
  
  
  Clinicians should be prudent when interpreting the results of published trials and some meta-analyses - such as those conducted by scientists working for the sponsor company or those that only include published trials. Prescribers, however, should be confident when prescribing drugs following the summary of product characteristics, since regulatory agencies have access to all clinical trial results.
authors.affiliation: Clinical Research, BUC (Biosciences UAM+CSIC) Program, International Campus of Excellence, Universidad Autónoma de Madrid, Ciudad Universitaria de Cantoblanco, c/Einstein 3, 28049, Madrid, Spain. rfdalre@gmail.com.
authors.forename: Rafael
authors.initials: R
authors.lastname: Dal-Ré
authors.affiliation: Department of Psychiatry, School of Medicine, University of Oviedo, C/ San Francisco, 1, 33003, Oviedo, Asturias, Spain.|CIBERSAM, Madrid, Spain.
authors.forename: Julio
authors.initials: J
authors.lastname: Bobes
authors.affiliation: Department of Clinical, Neuro and Developmental Psychology, Vrije Universiteit Amsterdam, De Boelelaan 1105, 1081 HV, Amsterdam, The Netherlands.|EMGO Institute for Health and Care Research, Amsterdam, The Netherlands.
authors.forename: Pim
authors.initials: P
authors.lastname: Cuijpers
mesh_terms: D015982:Bias; D002986:Clinical Trials as Topic / Q000379:methods*; D006801:Humans; D001523:Mental Disorders / Q000175:diagnosis / Q000523:psychology / Q000628:therapy*; D000071076:Network Meta-Analysis as Topic; D017063:Outcome Assessment, Health Care; D011594:Psychometrics; D017594:Publication Bias; D012107:Research Design; D018401:Sample Size; D016896:Treatment Outcome
keywords: Clinical trials; Meta-analysis; Outcome reporting bias; Pharmacotherapy; Psychotherapy; Publication bias