title: Implications of pain in generalized anxiety disorder: efficacy of duloxetine.
abstract: OBJECTIVE
  To conduct a post hoc evaluation of the prevalence of clinically significant pain and the efficacy of duloxetine in patients with generalized anxiety disorder (GAD) and concurrent pain.
  
  
  METHODS
  Data from two 9- to 10-week double-blind, placebo-controlled, randomized clinical trials of duloxetine (60 to 120 mg) in DSM-IV-defined GAD were analyzed (study 1 was conducted from July 2004 to September 2005; study 2 was conducted from August 2004 to June 2005). Efficacy was assessed with the Hamilton Rating Scale for Anxiety (HAM-A), visual analog scales (VAS) for pain, the Hospital Anxiety Depression Scale (HADS), the Clinical Global Impressions-Improvement of Illness (CGI-I) scale, the Patient Global Impressions-Improvement (PGI-I) scale, and the Sheehan Disability Scale (SDS) global functional impairment scale.
  
  
  RESULTS
  Of 840 patients randomly assigned to treatment, 61.3% (302 duloxetine, 213 placebo) had VAS scores ≥ 30 mm on at least 1 of the pain scales, indicating clinically significant pain. Among those patients with concurrent pain at baseline, change from baseline to endpoint in the HAM-A total score (42.9% change in mean scores for duloxetine, 31.4% for placebo), HADS anxiety scale (40.3% vs. 22.8%), HADS depression scale (36.1% vs. 20.5%), HAM-A psychic factor (45.9% vs. 29.9%), and SDS global functional improvement score (45.5% vs. 22.1%) was significantly (all p's < .001) greater for duloxetine compared with placebo. Improvement on the CGI-I (p = .003) and PGI-I (p < .001) was also significantly greater for duloxetine. Response (HAM-A total score decrease ≥ 50%) (49% vs. 29%) and remission (HAM-A total score ≤ 7 at endpoint) (29% vs. 18%) rates were significantly greater for duloxetine compared with placebo (p < .001 and p = .041, respectively). Duloxetine demonstrated statistically significantly greater reduction in pain on all 6 VAS pain scales (all p's < .001 except headaches with p < .002) (for duloxetine, percent change in means from baseline to endpoint ranged from 40.1% to 45.2% across the 6 VAS scales; for placebo, 22.0% to 26.3%).
  
  
  CONCLUSIONS
  Duloxetine, relative to placebo, improves anxiety symptoms, pain, and functional impairment among patients with GAD with concurrent clinically significant pain.
  
  
  BACKGROUND
  clinicaltrials.gov Identifiers: NCT00122824 (study 1) and NCT00475969 (study 2).
authors.affiliation: Hartford Research Group, Cincinnati, Ohio, USA. jhartford@communityresearch.com
authors.forename: James T
authors.initials: JT
authors.lastname: Hartford
authors.forename: Jean
authors.initials: J
authors.lastname: Endicott
authors.forename: Susan G
authors.initials: SG
authors.lastname: Kornstein
authors.forename: Christer
authors.initials: C
authors.lastname: Allgulander
authors.forename: Madelaine M
authors.initials: MM
authors.lastname: Wohlreich
authors.forename: James M
authors.initials: JM
authors.lastname: Russell
authors.forename: David G S
authors.initials: DG
authors.lastname: Perahia
authors.forename: Janelle S
authors.initials: JS
authors.lastname: Erickson