title: D-cycloserine enhances generalization of fear extinction in children.
abstract: BACKGROUND
  For exposure therapy to be successful, it is essential that fear extinction learning extends beyond the treatment setting. D-cycloserine (DCS) may facilitate treatment gains by increasing generalization of extinction learning, however, its effects have not been tested in children. We examined whether DCS enhanced generalization of fear extinction learning across different stimuli and contexts among children with specific phobias.
  
  
  METHODS
  The study was a double-blind placebo-controlled randomized controlled trial among dog or spider phobic children aged 6-14. Participants ingested either 50 mg of DCS (n = 18) or placebo (n = 17) before receiving a single prolonged exposure session to their feared stimulus. Return of fear was examined 1 week later to a different stimulus (a different dog or spider), presented in both the original treatment context and an alternate context. Avoidance and fear were measured with Behavior Approach Tests (BATs), where the child was asked to increase proximity to the stimulus while reporting their fear level.
  
  
  RESULTS
  There were no differences in BAT performance between groups during the exposure session or when a new stimulus was later presented in the treatment context. However, when the new stimulus was presented in a different context, relative to placebo, the DCS group showed less avoidance (P = .03) and less increase in fear (P = .04) with moderate effect sizes.
  
  
  CONCLUSIONS
  DCS enabled children to better retain their fear extinction learning. This new learning generalized to different stimuli and contexts.
authors.affiliation: Centre for Emotional Health, Department of Psychology, Macquarie University, Sydney, New South Wales, Australia.
authors.forename: Simon P
authors.initials: SP
authors.lastname: Byrne
authors.affiliation: Centre for Emotional Health, Department of Psychology, Macquarie University, Sydney, New South Wales, Australia.
authors.forename: Ronald M
authors.initials: RM
authors.lastname: Rapee
authors.affiliation: School of Psychology, University of New South Wales, Sydney, New South Wales, Australia.
authors.forename: Rick
authors.initials: R
authors.lastname: Richardson
authors.affiliation: CADE Clinic, Discipline of Psychiatry, Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Gin S
authors.initials: GS
authors.lastname: Malhi
authors.affiliation: Centre for Emotional Health, Department of Psychology, Macquarie University, Sydney, New South Wales, Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Jones
authors.affiliation: Centre for Emotional Health, Department of Psychology, Macquarie University, Sydney, New South Wales, Australia.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Hudson
mesh_terms: D000818:Animals; D002648:Child; D003131:Combined Modality Therapy; D003523:Cycloserine / Q000627:therapeutic use*; D004285:Dogs; D004311:Double-Blind Method; D005108:Extinction, Psychological / Q000187:drug effects*; D005239:Fear / Q000187:drug effects*; D005260:Female; D005793:Generalization, Psychological / Q000187:drug effects*; D006801:Humans; D007171:Implosive Therapy; D008297:Male; D010698:Phobic Disorders / Q000628:therapy*; D013112:Spiders
chemical_list: D003523:Cycloserine
keywords: anxiety; d-cycloserine; exposure therapy; fear extinction; obsessive-compulsive disorder; specific phobia