History of depressive and/or anxiety disorders as a predictor of treatment response: a post hoc analysis of a 12-week, randomized, double-blind, placebo-controlled trial of paroxetine controlled release in patients with fibromyalgia

Prog Neuropsychopharmacol Biol Psychiatry. 2009 Aug 31;33(6):996-1002. doi: 10.1016/j.pnpbp.2009.05.005. Epub 2009 May 9.


Background: Despite of a high comorbidity of depressive and/or anxiety disorders with fibromyalgia, information on the clinical implications of this comorbidity is limited but antidepressants are commonly prescribed to treat fibromyalgia in clinical practice. We investigated whether a history of depressive and/or anxiety disorders was associated with response to paroxetine controlled release (CR) in the treatment of fibromyalgia.

Methods: One hundred sixteen (116) fibromyalgia subjects were randomized to receive paroxetine CR or placebo for 12 weeks. The primary outcome was treatment response defined as >or=25% reduction in the Fibromyalgia Impact Questionnaire (FIQ) score. In multivariate logistic regression, we determined if a history of depression and/or anxiety disorders was an independent predictor of response to paroxetine CR.

Results: In logistic regression, the history of depression and/or anxiety did not predict treatment response as measured by >or=25% reduction in Fibromyalgia Impact Questionnaire (FIQ) score (OR=0.66, 95% CI=.29-1.49, Wald=0.97, p=0.32), while the drug status (paroxetine CR) was significantly associated with treatment response (OR=2.57, CI=1.2-5.61, Wald=5.5, p=0.02).

Conclusion: A significant proportion of patients with fibromyalgia had a history of anxiety and or depressive disorders. However response to treatment of fibromyalgia symptoms with paroxetine CR was not associated with a history of depressive and/or anxiety disorders. Our findings need to be confirmed in more adequately-powered and well-designed subsequent studies.

Publication types

  • Comparative Study
  • Controlled Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Anxiety Disorders / drug therapy*
  • Anxiety Disorders / epidemiology
  • Anxiety Disorders / psychology
  • Delayed-Action Preparations / administration & dosage
  • Depressive Disorder / drug therapy*
  • Depressive Disorder / epidemiology
  • Depressive Disorder / psychology
  • Double-Blind Method
  • Female
  • Fibromyalgia / drug therapy*
  • Fibromyalgia / epidemiology
  • Fibromyalgia / psychology
  • Humans
  • Male
  • Middle Aged
  • Pain Measurement / drug effects
  • Pain Measurement / methods
  • Paroxetine / administration & dosage*
  • Predictive Value of Tests
  • Treatment Outcome


  • Delayed-Action Preparations
  • Paroxetine