title: Dopaminergic activity in Tourette syndrome and obsessive-compulsive disorder.
abstract: Tourette syndrome (TS) and obsessive-compulsive disorder (OCD) both are neuropsychiatric disorders associated with abnormalities in dopamine neurotransmission. Aims of this study were to quantify striatal D2/3 receptor availability in TS and OCD, and to examine dopamine release and symptom severity changes in both disorders following amphetamine challenge. Changes in [(11)C]raclopride binding potential (BP(ND)) were assessed using positron emission tomography before and after administration of d-amphetamine (0.3 mg kg(-1)) in 12 TS patients without comorbid OCD, 12 OCD patients without comorbid tics, and 12 healthy controls. Main outcome measures were baseline striatal D2/3 receptor BP(ND) and change in BP(ND) following amphetamine as a measure of dopamine release. Voxel-based analysis revealed significantly decreased baseline [(11)C]raclopride BP(ND) in bilateral putamen of both patient groups vs. healthy controls, differences being more pronounced in the TS than in the OCD group. Changes in BP(ND) following amphetamine were not significantly different between groups. Following amphetamine administration, tic severity increased in the TS group, which correlated with BP(ND) changes in right ventral striatum. Symptom severity in the OCD group did not change significantly following amphetamine challenge and was not associated with changes in BP(ND). This study provides evidence for decreased striatal D2/3 receptor availability in TS and OCD, presumably reflecting higher endogenous dopamine levels in both disorders. In addition, it provides the first direct evidence that ventral striatal dopamine release is related to the pathophysiology of tics.
authors.affiliation: Department of Psychiatry, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands; The Netherlands Institute for Neuroscience, An Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, the Netherlands. Electronic address: ddenys@gmail.com.
authors.forename: Damiaan
authors.initials: D
authors.lastname: Denys
authors.forename: Froukje
authors.initials: F
authors.lastname: de Vries
authors.forename: Danielle
authors.initials: D
authors.lastname: Cath
authors.forename: Martijn
authors.initials: M
authors.lastname: Figee
authors.forename: Nienke
authors.initials: N
authors.lastname: Vulink
authors.forename: Dick J
authors.initials: DJ
authors.lastname: Veltman
authors.forename: Thalia F
authors.initials: TF
authors.lastname: van der Doef
authors.forename: Ronald
authors.initials: R
authors.lastname: Boellaard
authors.forename: Herman
authors.initials: H
authors.lastname: Westenberg
authors.forename: Anton
authors.initials: A
authors.lastname: van Balkom
authors.forename: Adriaan A
authors.initials: AA
authors.lastname: Lammertsma
authors.forename: Bart N M
authors.initials: BN
authors.lastname: van Berckel
mesh_terms: D000328:Adult; D002250:Carbon Radioisotopes; D016022:Case-Control Studies; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism; D003913:Dextroamphetamine / Q000494:pharmacology; D004298:Dopamine / Q000378:metabolism*; D018492:Dopamine Antagonists; D018765:Dopamine Uptake Inhibitors / Q000494:pharmacology; D005260:Female; D059907:Functional Neuroimaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D009771:Obsessive-Compulsive Disorder / Q000000981:diagnostic imaging / Q000378:metabolism*; D011569:Psychiatric Status Rating Scales; D020891:Raclopride; D011877:Radionuclide Imaging; D017448:Receptors, Dopamine D2 / Q000378:metabolism; D050637:Receptors, Dopamine D3 / Q000378:metabolism; D005879:Tourette Syndrome / Q000000981:diagnostic imaging / Q000378:metabolism*
chemical_list: D002250:Carbon Radioisotopes; D018492:Dopamine Antagonists; D018765:Dopamine Uptake Inhibitors; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D020891:Raclopride; D003913:Dextroamphetamine; D004298:Dopamine
keywords: Amphetamine; Dopamine; Obsessive-compulsive disorder; Positron emission tomography; Tourette syndrome; [(11)C]raclopride