학술논문
Higher striatal dopamine transporter density in PTSD: an in vivo SPECT study with [[sup.99m]TC]TRODAT-1
Document Type
Report
Author
Source
Psychopharmacology. November 15, 2012, Vol. 224 Issue 2, p337, 9 p.
Subject
Language
English
ISSN
0033-3158
Abstract
Introduction Posttraumatic stress disorder (PTSD) is a maladaptative stress response that may occur when an individual is exposed to a severe, psychologically traumatic event. It is characterized by reexperiencing, avoidance/numbing, [...]
Rationale Some evidence suggests a hyperdopaminergic state in posttraumatic stress disorder (PTSD). The 9-repetition allele (9R) located in the 3' untranslated region of the dopamine transporter (DAT) gene (SLC6A3) is more frequent among PTSD patients. In vivo molecular imaging studies have shown that healthy 9R carriers have increased striatal DAT binding. However, no prior study evaluated in vivo striatal DAT density in PTSD. Objectives The objective of this study was to evaluate in vivo striatal DAT density in PTSD. Methods Twenty-one PTSD subjects and 21 control subjects, who were traumatized but asymptomatic, closely matched comparison subjects evaluated with the Clinician-Administered PTSD Scale underwent a single-photon emission computed tomography scan with [[sup.99m]TC]-TRODAT-1. DAT binding potential (DAT-BP) was calculated using the striatum as the region of the interest and the occipital cortex as a reference region. Results PTSD patients had greater bilateral striatal DATBP (mean ± SD; left, 1.80 ± 0.42; right, 1.78 ± 0.40) than traumatized control subjects (left, 1.62 ± 0.32; right, 1.61 ± 0.31; p = 0.039 for the left striatum and p = 0.032 for the right striatum). Conclusions These results provide the first in vivo evidence for increased DAT density in PTSD. Increases in DAT density may reflect higher dopamine turnover in PTSD, which could contribute to the perpetuation and potentiation of exaggerated fear responses to a given event associated with the traumatic experience. Situations that resemble the traumatic event turn to be interpreted as highly salient (driving attention, arousal, and motivation) in detriment of other daily situations. Keywords Posttraumatic stress disorder * Depression * Corpus striatum * Dopamine transporter * Single-photon emission computed tomography
Rationale Some evidence suggests a hyperdopaminergic state in posttraumatic stress disorder (PTSD). The 9-repetition allele (9R) located in the 3' untranslated region of the dopamine transporter (DAT) gene (SLC6A3) is more frequent among PTSD patients. In vivo molecular imaging studies have shown that healthy 9R carriers have increased striatal DAT binding. However, no prior study evaluated in vivo striatal DAT density in PTSD. Objectives The objective of this study was to evaluate in vivo striatal DAT density in PTSD. Methods Twenty-one PTSD subjects and 21 control subjects, who were traumatized but asymptomatic, closely matched comparison subjects evaluated with the Clinician-Administered PTSD Scale underwent a single-photon emission computed tomography scan with [[sup.99m]TC]-TRODAT-1. DAT binding potential (DAT-BP) was calculated using the striatum as the region of the interest and the occipital cortex as a reference region. Results PTSD patients had greater bilateral striatal DATBP (mean ± SD; left, 1.80 ± 0.42; right, 1.78 ± 0.40) than traumatized control subjects (left, 1.62 ± 0.32; right, 1.61 ± 0.31; p = 0.039 for the left striatum and p = 0.032 for the right striatum). Conclusions These results provide the first in vivo evidence for increased DAT density in PTSD. Increases in DAT density may reflect higher dopamine turnover in PTSD, which could contribute to the perpetuation and potentiation of exaggerated fear responses to a given event associated with the traumatic experience. Situations that resemble the traumatic event turn to be interpreted as highly salient (driving attention, arousal, and motivation) in detriment of other daily situations. Keywords Posttraumatic stress disorder * Depression * Corpus striatum * Dopamine transporter * Single-photon emission computed tomography