title: Dissection of the factors driving the placebo effect in hypnotic treatment of depressed insomniacs.
abstract: OBJECTIVE
  Our prior work has shown that there is improvement in self-reported sleep in persons receiving placebo in hypnotic clinical trials. We examined the components of the "placebo response" in a hypnotic clinical trial.
  
  
  METHODS
  This was an exploratory analysis of a randomized, double-blind clinical trial of eszopiclone versus placebo in the treatment of persons with depression and insomnia who were also receiving fluoxetine at a clinic of a teaching hospital. Sixty adults with both depression and insomnia symptoms, who were free of significant primary sleep disorders, received open-label fluoxetine for 9weeks. Patients were further randomized 1:1 to receive either masked eszopiclone 3mg or placebo at bedtime after the first week of fluoxetine. We examined the respective contributions of three factors associated with the "placebo effect": (1) regression to the mean, (2) expectancy, and (3) social desirability.
  
  
  RESULTS
  There was evidence for regression to the mean for the continuous measurement of the Insomnia Severity Index (ISI) and the Hamilton Depression Rating Scale. There was evidence for expectancy in self-reported Wake After Sleep Onset, continuous measurement of ISI, and dichotomous remission/non-remitter measurement of ISI. There was evidence of social desirability affecting self-reported Total Sleep Time.
  
  
  CONCLUSIONS
  Factors that have been associated with the "placebo effect" are operating in hypnotic clinical trials. However, the role of each factor differs depending upon which self-reported variable is being considered. The findings have implications for clinical trial design in insomnia.
authors: Department of Psychiatry and Behavioral Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA. vmccall@wfubmc.edu
authors: W Vaughn
authors: WV
authors: McCall
authors: Ralph
authors: R
authors: D'Agostino
authors: Peter B
authors: PB
authors: Rosenquist
authors: James
authors: J
authors: Kimball
authors: Niki
authors: N
authors: Boggs
authors: Barbara
authors: B
authors: Lasater
authors: Jill
authors: J
authors: Blocker
references: Arch Gen Psychiatry. 2008 Feb;65(2):220-31
references: 18250260
references: Psychopharmacology (Berl). 2005 Oct;181(4):761-70
references: 15986193
references: JAMA. 1961 Jul 1;176:1102-7
references: 13688614
references: Sleep Med. 2003 Jan;4(1):57-62
references: 14592361
references: Sports Med. 2003;33(8):575-84
references: 12797839
references: Int J Clin Pharmacol Ther. 2005 Aug;43(8):355-9
references: 16119510
references: Arch Gerontol Geriatr. 1999 Mar-Apr;28(2):85-98
references: 15374088
references: Br Med J. 1976 Jan 24;1(6003):195-6
references: 1247770
references: J Psychiatr Res. 1975 Nov;12(3):189-98
references: 1202204
references: J Speech Lang Hear Res. 2003 Dec;46(6):1340-51
references: 14700359
references: J Clin Psychiatry. 2007 Aug;68(8):1213-7
references: 17854245
references: JAMA. 2001 Apr 11;285(14):1856-64
references: 11308399
references: J Clin Sleep Med. 2010 Aug 15;6(4):322-9
references: 20726279
references: Sleep Med Rev. 2005 Oct;9(5):381-9
references: 16109495
references: J Clin Psychiatry. 2010 Mar;71(3):270-9
references: 20122371
references: Scand J Work Environ Health. 2000 Aug;26(4):363-7
references: 10994804
references: Pain. 2001 Jul;93(1):77-84
references: 11406341
references: J Neurol Neurosurg Psychiatry. 1960 Feb;23:56-62
references: 14399272
references: J Nerv Ment Dis. 2003 Apr;191(4):211-8
references: 12695731
references: J Am Acad Dermatol. 2007 Dec;57(6):972-6
references: 17884244
references: J Clin Epidemiol. 2006 Apr;59(4):331-5
references: 16549251
references: Curr Med Res Opin. 2009 Oct;25(10):2487-94
references: 19689221
references: J Clin Psychiatry. 2001 Jun;62(6):453-63
references: 11465523
references: Psychol Med. 2005 May;35(5):743-9
references: 15918351
references: Clin Pharmacol Ther. 2001 May;69(5):297-307
references: 11371997
references: Sleep. 2008 Apr;31(4):489-95
references: 18457236
references: Sleep Med. 2001 Jul;2(4):297-307
references: 11438246
references: JAMA. 2008 Mar 5;299(9):1016-7
references: 18319411
references: Clin Chem Lab Med. 2004 Feb;42(2):241-2
references: 15061369
references: J Clin Sleep Med. 2009 Oct 15;5(5):454-8
references: 19961031
references: J Pers Assess. 2002 Oct;79(2):286-305
references: 12425392
references: J Sleep Res. 2007 Mar;16(1):77-84
references: 17309766
references: J Clin Psychiatry. 1997;58 Suppl 11:30-8
references: 9363046
references: Clin Pharmacol Ther. 2001 May;69(5):286-96
references: 11371996
references: Sleep. 2004 Dec 15;27(8):1567-96
references: 15683149