title: D-cycloserine enhancement of exposure therapy for social anxiety disorder depends on the success of exposure sessions.
abstract: OBJECTIVE
  The evidence for the efficacy of D-cycloserine (DCS) for augmenting cognitive behavioral therapy (CBT) for anxiety disorders has been mixed. Guided by preclinical research and initial findings from a small-scale study involving humans, we tested the hypothesis that DCS enhancement of exposure therapy would be specific to successful exposure sessions.
  
  
  METHODS
  Medication-free adults with generalized social anxiety disorder (N = 145) received 50 mg of DCS or placebo 1 h before each of 5 exposure sessions that were part of a standardized 12-session group CBT protocol. Participants provided fear ratings at the beginning and just before the end of exposure exercises. Independent raters, blind to group assignment, administered the clinical global impression improvement and severity scales at each session and at posttreatment.
  
  
  RESULTS
  Mixed-effects analyses revealed that, among patients who reported low fear at the end of an exposure session, those who had received DCS evidenced significantly greater clinical improvement at the next session, relative to those who had received placebo. In contrast, when exposure end fear was high, patients receiving DCS exhibited less clinical improvement at the following session than patients receiving placebo. Similarly, patients who had received DCS evidenced lower clinical severity at posttreatment, relative to patients who had received placebo, only when their average end fear for medication-augmented sessions had been in the low to moderate range. Finally, these moderating effects of exposure success as indexed by end fear were not better accounted for by within-session extinction.
  
  
  CONCLUSIONS
  The efficacy of DCS for augmenting exposure-based CBT depends on the success of exposure sessions. These findings may help guide the development of an algorithm for the effective use of DCS for augmenting exposure-based CBT.
  
  
  BACKGROUND
  http://www.ClinicalTrials.gov, ID# NCT00633984, http://www.clinicaltrials.gov/ct2/show/NCT00633984.
authors.affiliation: Department of Psychology, Southern Methodist University, USA. jsmits@smu.edu
authors.forename: Jasper A J
authors.initials: JA
authors.lastname: Smits
authors.forename: David
authors.initials: D
authors.lastname: Rosenfield
authors.forename: Michael W
authors.initials: MW
authors.lastname: Otto
authors.forename: Luana
authors.initials: L
authors.lastname: Marques
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Davis
authors.forename: Alicia E
authors.initials: AE
authors.lastname: Meuret
authors.forename: Naomi M
authors.initials: NM
authors.lastname: Simon
authors.forename: Mark H
authors.initials: MH
authors.lastname: Pollack
authors.forename: Stefan G
authors.initials: SG
authors.lastname: Hofmann
mesh_terms: D000328:Adult; D000928:Antidepressive Agents / Q000627:therapeutic use*; D001008:Anxiety Disorders / Q000188:drug therapy* / Q000523:psychology / Q000534:rehabilitation*; D003523:Cycloserine / Q000627:therapeutic use*; D004311:Double-Blind Method; D005239:Fear / Q000523:psychology; D005260:Female; D006801:Humans; D007171:Implosive Therapy; D008297:Male; D015233:Models, Statistical; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D000928:Antidepressive Agents; D003523:Cycloserine
keywords: CBT; Cognitive behavioral therapy; Exposure therapy; Fear extinction; Moderators; Social anxiety disorder; Social phobia; d-cycloserine