Central noradrenergic responsiveness to a clonidine challenge in Generalized Anxiety Disorder: a single photon emission computed tomography study

Kalk, Nicola J., Melichar, Jan, Holmes, Robin B., Taylor, Lindsay G., Daglish, Mark R.C., Hood, Sean, Edwards, Tom, Lennox-Smith, Alan, Lingford-Hughes, Anne R. and Nutt, David J. (2012) Central noradrenergic responsiveness to a clonidine challenge in Generalized Anxiety Disorder: a single photon emission computed tomography study. Journal of Psychopharmacology, 26 4: 452-460. doi:10.1177/0269881111415730


Author Kalk, Nicola J.
Melichar, Jan
Holmes, Robin B.
Taylor, Lindsay G.
Daglish, Mark R.C.
Hood, Sean
Edwards, Tom
Lennox-Smith, Alan
Lingford-Hughes, Anne R.
Nutt, David J.
Title Central noradrenergic responsiveness to a clonidine challenge in Generalized Anxiety Disorder: a single photon emission computed tomography study
Journal name Journal of Psychopharmacology   Check publisher's open access policy
ISSN 0269-8811
1461-7285
Publication date 2012-04
Year available 2011
Sub-type Article (original research)
DOI 10.1177/0269881111415730
Volume 26
Issue 4
Start page 452
End page 460
Total pages 9
Place of publication London, United Kingdom
Publisher Sage Publications
Collection year 2012
Language eng
Abstract Generalized Anxiety Disorder (GAD) may involve hypo-responsiveness of noradrenaline a2 receptors. To test this hypothesis, we used 99mTc-hexamethyl- propylene-amine-oxime (HMPAO) Single Photon Emission Computed Tomography to measure regional cerebral perfusion in patients with untreated GAD, venlafaxine-treated patients and healthy controls during word generation before and after clonidine. Concurrent psychological and physiological measures supported noradrenergic hypofunction in GAD in some cases. A single-day split-dose technique was used. Images were processed using SPM5 (Institute of Neurology). Factorial analysis revealed no significant results. Exploratory analyses were done. Regional perfusion during verbal fluency differed by group pre-clonidine. Compared with healthy controls, patients with untreated GAD displayed increased perfusion in the left Broca’s area and left occipitotemporal region. Treated GAD patients displayed increased cerebellar perfusion bilaterally. Clonidine was associated with different changes in cerebral perfusion in each group. Increases were seen in the right supra-marginal gyrus in healthy subjects, in the left pre-central gyrus in treated GAD patients and in the right cerebellum and middle frontal gyrus in untreated GAD patients. Despite these differences, the findings were not consistent with a noradrenergic hypo-responsiveness hypothesis, as the treated group showed a different pattern of response rather than a normalization of response.
Keyword Clonidine
Generalized anxiety disorder
Neuroimaging
Noradrenergic
SPECT
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ
Additional Notes First published on 17 September 2011.

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2012 Collection
School of Medicine Publications
 
Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 4 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 4 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Fri, 14 Oct 2011, 16:51:46 EST by Dr Mark Daglish on behalf of Psychiatry - Royal Brisbane and Women's Hospital