Elevated brain serotonin transporter availability in patients with obsessive-compulsive disorder.
BACKGROUND
A central serotonergic dysfunction is considered to be involved in the pathophysiology of obsessive-compulsive disorder (OCD). The aim of this study was to investigate the serotonin transporter availability in patients with OCD as an in vivo marker of the central serotonergic system.


METHODS
Nine unmedicated (7 drug-naive) patients with OCD and 10 healthy control subjects were included and received single photon emission computed tomography (SPECT) 20.75 +/- 1.51 hours after injection of a mean 147.20 +/- 6.74 MBq [(123)I]-2beta-carbomethoxy-3beta-(4-iodophenyl)tropane ([(123)I]beta-CIT). As a measure of brain serotonin transporter availability, a ratio of specific-to-nonspecific [(123)I]beta-CIT binding for the midbrain-pons (V(3)" = [midbrain/pons-occipital]/occipital) was used.


RESULTS
Mean specific-to-nonspecific ratios showed a 25% higher midbrain-pons [(123)I]beta-CIT binding in the patients as compared with healthy controls (2.26 +/-.37 vs. 1.81 +/-.23, p <.01). The difference remained significant after adjustment for clinical variables and controlling for age and gender. Stratification of the patients according to onset of the disorder revealed significant differences between controls and patients with early (childhood, adolescence) but not late (adult) onset of OCD.


CONCLUSIONS
The study provides evidence of a serotonergic dysfunction in patients with OCD and suggests a serotonergic component in the pathophysiology of the disorder.
Pogarell
Oliver
O
Department of Psychiatry, Ludwig-Maximilians-University, Munich, Germany.
Hamann
Christine
C
Pöpperl
Gabriele
G
Juckel
Georg
G
Choukèr
Martina
M
Zaudig
Michael
M
Riedel
Michael
M
Möller
Hans-Jürgen
HJ
Hegerl
Ulrich
U
Tatsch
Klaus
K
D000328:Adult; D001921:Brain / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000378:metabolism*; D001923:Brain Chemistry; D002352:Carrier Proteins / Q000378:metabolism*; D016022:Case-Control Studies; D003042:Cocaine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism*; D026901:Membrane Transport Proteins; D008875:Middle Aged; D009419:Nerve Tissue Proteins; D009771:Obsessive-Compulsive Disorder / Q000000981:diagnostic imaging / Q000378:metabolism*; D050486:Serotonin Plasma Membrane Transport Proteins; D012737:Sex Factors; D013223:Statistics as Topic; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods
D002352:Carrier Proteins; D007457:Iodine Radioisotopes; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins; C069723:2beta-carbomethoxy-3beta-(4-iodophenyl)tropane; D003042:Cocaine