Serotonin and dopamine are putatively involved in the etiology and treatment of anxiety disorders, but positron emission tomography (PET) studies probing the two neurotransmitters in the same individuals are lacking. The aim of this multitracer PET study was to evaluate the regional expression and co-expression of the transporter proteins for serotonin (SERT) and dopamine (DAT) in patients with social anxiety disorder (SAD). Voxel-wise binding potentials (BP_ND) for SERT and DAT were determined in 27 patients with SAD and 43 age- and sex-matched healthy controls, using the radioligands [¹¹C]DASB (3-amino-4-(2-dimethylaminomethylphenylsulfanyl)-benzonitrile) and [¹¹C]PE2I (N-(3-iodopro-2E-enyl)-2beta-carbomethoxy-3beta-(4′-methylphenyl)nortropane). Results showed that, within transmitter systems, SAD patients exhibited higher SERT binding in the nucleus accumbens while DAT availability in the amygdala, hippocampus, and putamen correlated positively with symptom severity. At a more lenient statistical threshold, SERT and DAT BP_ND were also higher in other striatal and limbic regions in patients, and correlated with symptom severity, whereas no brain region showed higher binding in healthy controls. Moreover, SERT/DAT co-expression was significantly higher in SAD patients in the amygdala, nucleus accumbens, caudate, putamen, and posterior ventral thalamus, while lower co-expression was noted in the dorsomedial thalamus. Follow-up logistic regression analysis confirmed that SAD diagnosis was significantly predicted by the statistical interaction between SERT and DAT availability, in the amygdala, putamen, and dorsomedial thalamus. Thus, SAD was associated with mainly increased expression and co-expression of the transporters for serotonin and dopamine in fear and reward-related brain regions. Resultant monoamine dysregulation may underlie SAD symptomatology and constitute a target for treatment.

血清素和多巴胺被推定与焦虑症的病因学和治疗有关，但缺乏对同一个体的两种神经递质进行正电子发射断层扫描 (PET) 研究。这项多示踪剂 PET 研究的目的是评估社交焦虑症 (SAD) 患者血清素 (SERT) 和多巴胺 (DAT) 转运蛋白的区域表达和共表达。在 27 名 SAD 患者和 43 名年龄和性别匹配的健康对照中，使用放射性配体 [ ¹¹ C]DASB (3-amino-4-(2-dimethylaminomethylphenylsulfanyl ) 测定了 SERT 和 DAT 的体素结合电位 (BP _ND ) )-苯甲腈)和[ ¹¹C]PE2I (N-(3-iodopro-2E-enyl)-2beta-carbomethoxy-3beta-(4'-methylphenyl)nortropane)。结果表明，在发射器系统中，SAD 患者在伏隔核中表现出更高的 SERT 结合，而杏仁核、海马体和壳核中的 DAT 可用性与症状严重程度呈正相关。在更宽松的统计阈值下，SERT 和 DAT BP _ND在患者的其他纹状体和边缘区域也更高，并且与症状严重程度相关，而在健康对照中没有大脑区域显示出更高的结合。此外，SERT/DAT 共表达在 SAD 患者的杏仁核、伏隔核、尾状核、壳核和后腹侧丘脑中显着更高，而背内侧丘脑中的共表达较低。后续逻辑回归分析证实，在杏仁核、壳核和背内侧丘脑中，SERT 和 DAT 可用性之间的统计相互作用显着预测了 SAD 诊断。因此，SAD 主要与恐惧和奖赏相关大脑区域中血清素和多巴胺转运蛋白的表达和共表达增加有关。