Dopamine transporter density may be associated with the depressed affect in healthy subjects.
OBJECTIVE
Increased levels of dopamine transporter (DAT) binding have been reported in patients with major depression. We used the selective DAT radiopharmaceutical Tc-TRODAT-1 and SPECT brain imaging, to examine differences in DAT levels in healthy subjects with and without depressive affect.


METHODS
We compared striatal DAT binding affinity in 73 healthy subjects to their scores on the depressive symptoms subscale of the Profile of Mood States (POMS). Regions of interest in the basal ganglia of the brain were examined. Distribution volume ratios (DVRs) of Tc-TRODAT-1 binding affinity were calculated from the SPECT scan data, and comparisons among subjects with low and high depressive symptom ratings were calculated using unpaired t-tests and the Pearson correlation.


RESULTS
We observed a greater Tc-TRODAT-1 DVR in the right caudate of subjects with high POMS mood scores compared to subjects with low scores on depressive items on the POMS (2.99+/-0.35 and 2.79+/-0.35, respectively; P=0.009). There was also a weak, but significant correlation between higher Tc-TRODAT-1 DVRs in the right caudate and depressive symptoms scores (r=0.23, P=0.05).


CONCLUSIONS
These data suggest that Tc-TRODAT-1 binding affinity to DAT sites may be associated with depressive affect in healthy subjects. The finding also supports prior observations of greater Tc-TRODAT-1 DVRs in patients with major depressive episode.
Newberg
Andrew
A
Department of Radiology, Division of Nuclear Medicine, University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104, USA. andrew.newberg@uphs.upenn.edu
Amsterdam
Jay
J
Shults
Justine
J
D000328:Adult; D001921:Brain / Q000473:pathology; D003865:Major Depressive Disorder / Q000378:metabolism*; D050483:Dopamine Plasma Membrane Transport Proteins / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008024:Ligands; D026901:Membrane Transport Proteins / Q000737:chemistry; D008875:Middle Aged; D015609:Organotechnetium Compounds / Q000494:pharmacology; D011699:Putamen / Q000378:metabolism / Q000473:pathology*; D019275:Radiopharmaceuticals / Q000494:pharmacology; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014326:Tropanes / Q000494:pharmacology
D050483:Dopamine Plasma Membrane Transport Proteins; D008024:Ligands; D026901:Membrane Transport Proteins; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D014326:Tropanes; C104196:technetium Tc 99m TRODAT-1