PET imaging of serotonin type 2A receptors in late-life neuropsychiatric disorders.
OBJECTIVE
To determine whether there are abnormalities in the in vivo status of the serotonin type 2A (5-HT2A) receptor in late-life depression and Alzheimer's disease, the authors used positron emission tomography (PET) to assess patients with these two conditions and healthy subjects.


METHODS
PET was performed by using [18F]altanserin to evaluate 5-HT2A receptor binding in 11 elderly patients with depression (four men, seven women; mean age = 65.0 years, SD = 5.5); nine Alzheimer's disease patients, including three with concurrent depression (two men, seven women; mean age = 69.7 years, SD = 5.0); and 10 age-matched healthy subjects (four men, six women; mean age = 69.8 years, SD = 5.0). Partial-volume correction of regional specific binding estimates was performed by using a method based on magnetic resonance imaging.


RESULTS
No significant abnormalities in [18F]altanserin binding (binding potential) were observed in the patients with late-life depression, and no effect of depression on binding potential was present within the Alzheimer's disease group. However, the patients with Alzheimer's disease had significantly lower binding than the normal subjects in several brain regions, including the anterior cingulate, prefrontal cortex, and sensorimotor cortex.


CONCLUSIONS
These results suggest that the 5-HT2A receptor is differentially affected in late-life depression and Alzheimer's disease, a finding that has implications for the etiological basis of mood and cognitive features of neuropsychiatric disorders of late life.
Meltzer
C C
CC
Department of Radiology, University of Pittsburgh, PA, USA. meltzer@radserv.arad.upmc.edu
Price
J C
JC
Mathis
C A
CA
Greer
P J
PJ
Cantwell
M N
MN
Houck
P R
PR
Mulsant
B H
BH
Ben-Eliezer
D
D
Lopresti
B
B
DeKosky
S T
ST
Reynolds
C F
CF
D000367:Age Factors; D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000378:metabolism*; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000378:metabolism; D003866:Depressive Disorder / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000378:metabolism; D005260:Female; D005462:Fluorine Radioisotopes; D006179:Gyrus Cinguli / Q000000981:diagnostic imaging / Q000378:metabolism; D006801:Humans; D007650:Ketanserin / Q000031:analogs & derivatives; D008279:Magnetic Resonance Imaging; D008297:Male; D017397:Prefrontal Cortex / Q000000981:diagnostic imaging / Q000378:metabolism; D044402:Receptor, Serotonin, 5-HT2A; D011985:Receptors, Serotonin / Q000378:metabolism*; D014055:Tomography, Emission-Computed
D005462:Fluorine Radioisotopes; D044402:Receptor, Serotonin, 5-HT2A; D011985:Receptors, Serotonin; C071983:altanserin; D007650:Ketanserin