Brain imaging techniques enable the visualization of serotonin transporter (SERT) occupancy as a measure of the proportion of SERT blocked by an antidepressant at a given dose. We aimed to systematically review the evidence on the relationship between antidepressant dose and SERT occupancy. We searched PubMed and Embase (last search 20 May 2021) for human in vivo, within-subject PET, or SPECT studies measuring SERT occupancy at any dose of any antidepressant with highly selective radioligands ([¹¹C]-DASB, [¹²³I]-ADAM, and [¹¹C]-MADAM). We summarized and visualized the dose-occupancy relationship for antidepressants across studies, overlaying the plots with a curve based on predicted values of a standard 2-parameter Michaelis–Menten model fitted using the observed data. We included seventeen studies of 10 different SSRIs, SNRIs, and serotonin modulators comprising a total of 294 participants, involving 309 unique occupancy measures. Overall, following the Michaelis–Menten equation, SERT occupancy increased with a higher dose in a hyperbolic relationship, with occupancy increasing rapidly at lower doses and reaching a plateau at approximately 80% at the usual minimum recommended dose. All the studies were small, only a few investigated the same antidepressant, dose, and brain region, and few reported information on factors that may influence SERT occupancy. The hyperbolic dose-occupancy relationship may provide mechanistic insight of relevance to the limited clinical benefit of dose-escalation in antidepressant treatment and the potential emergence of withdrawal symptoms. The evidence is limited by non-transparent reporting, lack of standardized methods, small sample sizes, and short treatment duration. Future studies should standardize the imaging and reporting procedures, measure occupancy at lower antidepressant doses, and investigate the moderators of the dose-occupancy relationship.

脑成像技术可以可视化血清素转运蛋白 (SERT) 的占有率，以衡量在给定剂量下被抗抑郁药阻断的 SERT 比例。我们旨在系统地回顾抗抑郁药剂量与 SERT 占用率之间关系的证据。我们在 PubMed 和 Embase（最后一次搜索时间为 2021 年 5 月 20 日）中搜索了人类体内、受试者体内 PET 或 SPECT 研究，这些研究测量了任何剂量的任何抗抑郁药与高选择性放射性配体（[ ¹¹ C]-DASB，[ ¹²³ I] -亚当，和 [ ¹¹C]-女士）。我们总结并可视化了跨研究的抗抑郁药的剂量-占用关系，用基于使用观察数据拟合的标准 2 参数 Michaelis-Menten 模型的预测值的曲线覆盖图。我们纳入了 10 种不同 SSRI、SNRI 和 5-羟色胺调节剂的 17 项研究，共有 294 名参与者，涉及 309 项独特的占用测量。总体而言，根据 Michaelis-Menten 方程，SERT 占用率随着剂量的增加呈双曲线关系增加，在较低剂量时占用率迅速增加，并在通常的最小推荐剂量下达到约 80% 的平台期。所有的研究都很小，只有少数研究了相同的抗抑郁药、剂量和大脑区域，并且很少报告可能影响 SERT 占用率的因素的信息。双曲线的剂量-占用关系可能提供与抗抑郁治疗中剂量递增的有限临床益处和可能出现的戒断症状相关的机制见解。证据受到不透明报告、缺乏标准化方法、样本量小和治疗持续时间短的限制。未来的研究应该标准化成像和报告程序，在较低的抗抑郁药剂量下测量占用率，并研究剂量-占用率关系的调节因素。和治疗时间短。未来的研究应该标准化成像和报告程序，在较低的抗抑郁药剂量下测量占用率，并研究剂量-占用率关系的调节因素。和治疗时间短。未来的研究应该标准化成像和报告程序，在较低的抗抑郁药剂量下测量占用率，并研究剂量-占用率关系的调节因素。