title: [123I]-beta-CIT SPECT imaging shows reduced thalamus-hypothalamus serotonin transporter availability in 24 drug-free obsessive-compulsive checkers.
abstract: Numerous findings indicate alterations in brain serotonin systems in obsessive-compulsive disorder (OCD). We investigated the in vivo availability of thalamus-hypothalamus serotonin transporters (SERT) in patients with DSM-IV OCD who displayed prominent behavioral checking compulsions (OC-checkers). Four hours after injection of [(123)I]-2beta-carbomethoxy-3beta-(4-iodophenyl)tropane ([(123)I]-beta-CIT), single photon emission computed tomography (SPECT) scans were performed in 24 medication-free non-depressed OC-checkers and 24 age- and gender-matched healthy controls. For quantification of brain serotonin transporter availability, a ratio of specific to non-displaceable [(123)I]-beta-CIT brain binding was used (V''(3)=(thalamus and hypothalamus-cerebellum)/cerebellum). Drug-free non-depressed OC-checkers showed an 18% reduced brain serotonin transporter availability in the thalamus and hypothalamus, as compared with healthy control subjects (1.38+/-0.19 vs 1.69+/-0.21; p<0.001). There was a strong negative correlation between severity of OC symptomatology (Y-BOCS scores) and SERT availability (r=-0.80; p<0.001). Moreover, we found a significant positive correlation between illness duration and serotonin transporter availability (r=0.43; p<0.05). This first report of significantly reduced [(123)I]-beta-CIT binding in the thalamus-hypothalamus region in OC-checkers suggests reduced brain serotonin transporter availability, which is more pronounced with increased severity of OC symptomatology and short duration of illness. The results provide direct evidence for an involvement of the serotonergic system in the pathophysiology of OCD.
authors.affiliation: Department of Psychiatry, Medical University of Vienna, Vienna, Austria. werner.zitterl@meduniwien.ac.at
authors.forename: Werner
authors.initials: W
authors.lastname: Zitterl
authors.forename: Martin
authors.initials: M
authors.lastname: Aigner
authors.forename: Thomas
authors.initials: T
authors.lastname: Stompe
authors.forename: Karin
authors.initials: K
authors.lastname: Zitterl-Eglseer
authors.forename: Karin
authors.initials: K
authors.lastname: Gutierrez-Lobos
authors.forename: Brigitte
authors.initials: B
authors.lastname: Schmidl-Mohl
authors.forename: Thomas
authors.initials: T
authors.lastname: Wenzel
authors.forename: Ulrike
authors.initials: U
authors.lastname: Demal
authors.forename: Georg
authors.initials: G
authors.lastname: Zettinig
authors.forename: Kurt
authors.initials: K
authors.lastname: Hornik
authors.forename: Kenneth
authors.initials: K
authors.lastname: Thau
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003042:Cocaine / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D007031:Hypothalamus / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000473:pathology; D011485:Protein Binding / Q000187:drug effects; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D050486:Serotonin Plasma Membrane Transport Proteins / Q000378:metabolism*; D018709:Statistics, Nonparametric; D013788:Thalamus / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000378:metabolism; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: D019275:Radiopharmaceuticals; D050486:Serotonin Plasma Membrane Transport Proteins; C069723:2beta-carbomethoxy-3beta-(4-iodophenyl)tropane; D003042:Cocaine