[123I] beta-CIT and single photon emission computed tomography reveal reduced brain serotonin transporter availability in bulimia nervosa.
BACKGROUND
Impaired serotonin transmission has been implicated in the pathophysiology of eating disorders. We investigated the in vivo availability of brain serotonin transporters and dopamine transporters in bulimia nervosa patients.


METHODS
Approximately 24 hours after injection of [123I]-2beta-carbomethoxy-3beta-(4-iodophenyl)tropane ([123I] beta-CIT), single photon emission computed tomography scans were performed in 10 medication-free, female bulimic patients and 10 age-matched, healthy females. For quantification of brain serotonin transporter and dopamine transporter availability, a ratio of specific to nonspecific [123I] beta-CIT brain binding was used (V(3)" = target region - cerebellum/cerebellum).


RESULTS
Drug-free bulimia nervosa patients showed a 17% reduced brain serotonin transporter availability in the hypothalamus and thalamus, as compared with healthy control subjects (2.4 +/- 0.4 vs. 2.9 +/- 0.4, p =.026), and a similar reduction in striatal dopamine transporter availability. There was a negative correlation of illness duration and serotonin transporter availability (r = -.65; p =.042) and a strong positive correlation between hypothalamic/thalamic and striatal V(3)" (r =.80, p <.001).


CONCLUSIONS
This first report of reduced [123I] beta-CIT binding in a relatively small group of patients with bulimia nervosa suggests a reduced hypothalamic and thalamic serotonin transporter availability in bulimia, which is more pronounced with longer duration of illness.
Department of General Psychiatry, University of Vienna, Vienna, Austria.
J
J
Tauscher
W
W
Pirker
M
M
Willeit
M
M
de Zwaan
U
U
Bailer
A
A
Neumeister
S
S
Asenbaum
C
C
Lennkh
N
N
Praschak-Rieder
T
T
Brücke
S
S
Kasper
D000293:Adolescent; D000328:Adult; D001667:Binding, Competitive / Q000502:physiology; D001693:Biological Transport, Active / Q000502:physiology; D001921:Brain / Q000378:metabolism*; D002032:Bulimia / Q000378:metabolism* / Q000628:therapy; D002352:Carrier Proteins / Q000378:metabolism*; D002531:Cerebellum / Q000378:metabolism; D015928:Cognitive Behavioral Therapy; D003863:Depression / Q000175:diagnosis / Q000523:psychology; D005260:Female; D006801:Humans; D019275:Radiopharmaceuticals; D012701:Serotonin / Q000378:metabolism*; D015899:Tomography, Emission-Computed, Single-Photon
D002352:Carrier Proteins; D019275:Radiopharmaceuticals; D012701:Serotonin