Lower availability of striatal dopamine transporter in generalized anxiety disorder: a preliminary two-ligand SPECT study.

Dopamine and serotonin have been indirectly found to be associated with generalized anxiety disorder (GAD). The aims of this study were to examine the availabilities of the striatal dopamine transporter (DAT) and the midbrain serotonin transporter (SERT) in patients with GAD. 12 patients with GAD and 12 sex-matched, age-matched, and smoking status-matched healthy controls were recruited. The availabilities of DAT and SERT were approximated using single-photon emission computed tomography, with [Tc]TRODAT-1 and [I]ADAM as the ligands. There were several missing data for six participants with GAD in the ADAM study because of a lack of the radioligand at the time of the experiment. The DAT availability in the striatum was significantly lower in the patients with GAD than in the healthy controls. However, the SERT availability did not differ between the two groups. The results with respect to the striatal DAT level suggested a potential role in the pathophysiology of GAD.