title: Dopamine D1 receptor binding in the striatum of patients with obsessive-compulsive disorder.
abstract: BACKGROUND
  Obsessive-compulsive disorder (OCD) is a chronic anxiety disorder of unknown aetiology. Psychopharmacological studies have suggested a role for the neurotransmitter serotonin however further evidence for serotonin in the aetiology of OCD is conflicted. The authors used positron emission tomography (PET) to examine the binding of the dopamine D(1) receptor antagonist [(11)C]-SCH23390 to D(1) receptors in the striatum of drug-free OCD patients compared with healthy controls.
  
  
  METHODS
  Seven drug-free patients (two drug naïve) with OCD and seven age, gender and education matched healthy controls underwent positron emission tomography with [(11)C]-SCH23390. Binding Potentials (BP) at D(1) receptors were calculated for the caudate nucleus and putamen. Correlations between BP values for basal ganglia regions and clinical measures were performed in OCD patients.
  
  
  RESULTS
  The BP for [(11)C]-SCH23390 at D(1) receptors in OCD patients was significantly reduced in both caudate nucleus (0.59+/-0.06 vs 0.88+/-0.06, p<0.05) and putamen (0.89+/-0.06 vs 1.14+/-0.06, p<0.05) compared with healthy controls. No correlations were found between D(1) BP and symptom measures.
  
  
  CONCLUSIONS
  The main limitations of this study are the small sample size and the PET methodology which does not allow for disaggregation of Bmax and Kd values for D(1) receptor binding of [(11)C]-SCH23390.
  
  
  CONCLUSIONS
  The finding of downregulation of D(1) receptors in the striatum of OCD patients suggests increased nigrostriatal dopaminergic drive in OCD. If confirmed, this finding provides support for trials of novel treatments in OCD based on dopaminergic system blockade.
authors.affiliation: Department of Psychiatry, University of Melbourne, Heidelberg, Victoria, Australia. jamesso@unimelb.edu.au
authors.forename: James S
authors.initials: JS
authors.lastname: Olver
authors.forename: Graeme
authors.initials: G
authors.lastname: O'Keefe
authors.forename: Gareth R
authors.initials: GR
authors.lastname: Jones
authors.forename: Graham D
authors.initials: GD
authors.lastname: Burrows
authors.forename: Henri J
authors.initials: HJ
authors.lastname: Tochon-Danguy
authors.forename: Uwe
authors.initials: U
authors.lastname: Ackermann
authors.forename: Andrew
authors.initials: A
authors.lastname: Scott
authors.forename: Trevor R
authors.initials: TR
authors.lastname: Norman
mesh_terms: D000328:Adult; D000368:Aged; D001552:Benzazepines / Q000493:pharmacokinetics*; D002250:Carbon Radioisotopes; D016022:Case-Control Studies; D002421:Caudate Nucleus / Q000000981:diagnostic imaging / Q000378:metabolism*; D018492:Dopamine Antagonists / Q000493:pharmacokinetics*; D015536:Down-Regulation; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009771:Obsessive-Compulsive Disorder / Q000000981:diagnostic imaging / Q000378:metabolism*; D049268:Positron-Emission Tomography; D011569:Psychiatric Status Rating Scales; D011699:Putamen / Q000000981:diagnostic imaging / Q000378:metabolism*; D017447:Receptors, Dopamine D1 / Q000378:metabolism*; D055815:Young Adult
chemical_list: D001552:Benzazepines; D002250:Carbon Radioisotopes; D018492:Dopamine Antagonists; D017447:Receptors, Dopamine D1; C534628:SCH 23390