title: Influence of baseline severity on antidepressant efficacy for anxiety disorders: meta-analysis and meta-regression.
abstract: Antidepressants are established first-line treatments for anxiety disorders, but it is not clear whether they are equally effective across the severity range.
  
  
  
  To examine the influence of baseline severity of anxiety on antidepressant efficacy for generalised anxiety disorder (GAD), social anxiety disorder (SAD), obsessive-compulsive disorder (OCD), post-traumatic stress disorder (PTSD) and panic disorder.
  
  
  
  Fifty-six trials of second-generation antidepressants for the short-term treatment of an anxiety disorder were included. Baseline and change scores were extracted for placebo and treatment groups in each trial. Mixed effects meta-regression was used to investigate the effects of treatment group, baseline severity and their interaction.
  
  
  
  Increased baseline severity did not predict greater improvement in drug groups compared with placebo groups. Standardised regression coefficients of the interaction term between baseline severity and treatment group were 0.04 (95% CI -0.13 to 0.20, P = 0.65) for GAD, -0.06 (95% CI -0.20 to 0.09, P = 0.43) for SAD, 0.04 (95% CI -0.07 to 0.16, P = 0.46) for OCD, 0.16 (95% CI -0.22 to 0.53, P = 0.37) for PTSD and 0.002 (95% CI -0.10 to 0.10, P = 0.96) for panic disorder. For OCD, baseline severity did predict improvement in both placebo and drug groups equally (β = 0.11, 95% CI 0.05 to 0.17, P = 0.001).
  
  
  
  No relationship between baseline severity and drug-placebo difference was found for anxiety disorders. These results suggest that if the efficacy of antidepressants is considered clinically relevant, they may be prescribed to patients with anxiety regardless of symptom severity.
authors.affiliation: Ymkje Anna de Vries, MSc, Peter de Jonge, PhD, Interdisciplinary Center Psychopathology and Emotion Regulation, Department of Psychiatry, University Medical Center Groningen, University of Groningen, The Netherlands; Edwin van den Heuvel, PhD, Department of Mathematics and Computer Science, Technical University Eindhoven, Eindhoven, The Netherlands; Erick H. Turner, MD, Behavioral Health and Neurosciences Division, Portland Veterans Affairs Medical Center, and Department of Psychiatry, Oregon Health and Science University, Portland, Oregon, USA; Annelieke M. Roest, PhD, Interdisciplinary Center Psychopathology and Emotion Regulation, Department of Psychiatry, University Medical Center Groningen, University of Groningen, The Netherlands y.a.de.vries@umcg.nl.
authors.forename: Ymkje Anna
authors.initials: YA
authors.lastname: de Vries
authors.affiliation: Ymkje Anna de Vries, MSc, Peter de Jonge, PhD, Interdisciplinary Center Psychopathology and Emotion Regulation, Department of Psychiatry, University Medical Center Groningen, University of Groningen, The Netherlands; Edwin van den Heuvel, PhD, Department of Mathematics and Computer Science, Technical University Eindhoven, Eindhoven, The Netherlands; Erick H. Turner, MD, Behavioral Health and Neurosciences Division, Portland Veterans Affairs Medical Center, and Department of Psychiatry, Oregon Health and Science University, Portland, Oregon, USA; Annelieke M. Roest, PhD, Interdisciplinary Center Psychopathology and Emotion Regulation, Department of Psychiatry, University Medical Center Groningen, University of Groningen, The Netherlands.
authors.forename: Peter
authors.initials: P
authors.lastname: de Jonge
authors.affiliation: Ymkje Anna de Vries, MSc, Peter de Jonge, PhD, Interdisciplinary Center Psychopathology and Emotion Regulation, Department of Psychiatry, University Medical Center Groningen, University of Groningen, The Netherlands; Edwin van den Heuvel, PhD, Department of Mathematics and Computer Science, Technical University Eindhoven, Eindhoven, The Netherlands; Erick H. Turner, MD, Behavioral Health and Neurosciences Division, Portland Veterans Affairs Medical Center, and Department of Psychiatry, Oregon Health and Science University, Portland, Oregon, USA; Annelieke M. Roest, PhD, Interdisciplinary Center Psychopathology and Emotion Regulation, Department of Psychiatry, University Medical Center Groningen, University of Groningen, The Netherlands.
authors.forename: Edwin
authors.initials: E
authors.lastname: van den Heuvel
authors.affiliation: Ymkje Anna de Vries, MSc, Peter de Jonge, PhD, Interdisciplinary Center Psychopathology and Emotion Regulation, Department of Psychiatry, University Medical Center Groningen, University of Groningen, The Netherlands; Edwin van den Heuvel, PhD, Department of Mathematics and Computer Science, Technical University Eindhoven, Eindhoven, The Netherlands; Erick H. Turner, MD, Behavioral Health and Neurosciences Division, Portland Veterans Affairs Medical Center, and Department of Psychiatry, Oregon Health and Science University, Portland, Oregon, USA; Annelieke M. Roest, PhD, Interdisciplinary Center Psychopathology and Emotion Regulation, Department of Psychiatry, University Medical Center Groningen, University of Groningen, The Netherlands.
authors.forename: Erick H
authors.initials: EH
authors.lastname: Turner
authors.affiliation: Ymkje Anna de Vries, MSc, Peter de Jonge, PhD, Interdisciplinary Center Psychopathology and Emotion Regulation, Department of Psychiatry, University Medical Center Groningen, University of Groningen, The Netherlands; Edwin van den Heuvel, PhD, Department of Mathematics and Computer Science, Technical University Eindhoven, Eindhoven, The Netherlands; Erick H. Turner, MD, Behavioral Health and Neurosciences Division, Portland Veterans Affairs Medical Center, and Department of Psychiatry, Oregon Health and Science University, Portland, Oregon, USA; Annelieke M. Roest, PhD, Interdisciplinary Center Psychopathology and Emotion Regulation, Department of Psychiatry, University Medical Center Groningen, University of Groningen, The Netherlands.
authors.forename: Annelieke M
authors.initials: AM
authors.lastname: Roest
mesh_terms: D000928:Antidepressive Agents / Q000494:pharmacology*; D001008:Anxiety Disorders / Q000188:drug therapy* / Q000503:physiopathology*; D006801:Humans; D012720:Severity of Illness Index
chemical_list: D000928:Antidepressive Agents