title: Clonidine challenge in childhood anxiety disorder.
abstract: OBJECTIVE
  To evaluate the neurohormonal and subjective mood response of children with anxiety disorder to clonidine challenge
  
  
  METHODS
  Children with DSM-IV diagnoses of anxiety disorder (ANX) (n = 24) and normal controls (n = 15) were given a challenge of intravenous clonidine (1.3 micrograms/kg) and provided neurohormonal and mood self-report assessment over a 180-minute period.
  
  
  RESULTS
  The ANX group differed from normal controls in Hamilton Anxiety Rating, Revised Children's Manifest Anxiety Scale score, and maximum change from baseline (delta max) in growth hormone (GH). Clonidine-stimulated GH concentration of the ANX group was significantly elevated compared with that of controls but returned to baseline within 2 hours. A subgroup with obsessive-compulsive disorder (OCD) (n = 9) had significantly higher delta max GH (17.5 +/- 10.1 ng/mL) than the group with other anxiety disorders (ANX-OCD) (9.1 +/- 5.8 ng/mL) and controls (5.7 +/- 4.1 ng/mL).
  
  
  CONCLUSIONS
  GH response to clonidine challenge is not blunted in ANX subjects. This finding is in contrast to adult disorder and suggests that adrenergic postsynaptic receptor down-regulation is not a feature of childhood anxiety. These findings suggest enhanced central adrenergic sensitivity in ANX which is most pronounced in OCD and argue against a neurobiological continuum from childhood to adult anxiety disorder.
authors.affiliation: Department of Psychiatry, Medical University of South Carolina, Charleston 29425, USA.
authors.forename: F R
authors.initials: FR
authors.lastname: Sallee
authors.forename: H
authors.initials: H
authors.lastname: Richman
authors.forename: G
authors.initials: G
authors.lastname: Sethuraman
authors.forename: D
authors.initials: D
authors.lastname: Dougherty
authors.forename: L
authors.initials: L
authors.lastname: Sine
authors.forename: S
authors.initials: S
authors.lastname: Altman-Hamamdzic
mesh_terms: D000293:Adolescent; D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D017668:Age of Onset; D000704:Analysis of Variance; D001008:Anxiety Disorders / Q000097:blood / Q000503:physiopathology* / Q000523:psychology; D015415:Biomarkers; D002648:Child; D003000:Clonidine / Q000494:pharmacology*; D005260:Female; D013006:Growth Hormone / Q000097:blood*; D006801:Humans; D008297:Male; D018709:Statistics, Nonparametric
chemical_list: D000316:Adrenergic alpha-Agonists; D015415:Biomarkers; D013006:Growth Hormone; D003000:Clonidine