Abstract：
Stimulants represent the first line pharmacological treatment for attention-deficit/hyperactivity disorder (ADHD) and are among the most prescribed psychopharmacological treatments. Their mechanism of action at synaptic level has been extensively studied. However, it is less clear how their mechanism of action determines clinically observed benefits. To help bridge this gap, we provide a comprehensive review of stimulant effects, with an emphasis on nuclear medicine and magnetic resonance imaging (MRI) findings. There is evidence that stimulant-induced modulation of dopamine and norepinephrine neurotransmission optimizes engagement of task-related brain networks, increases perceived saliency, and reduces interference from the default mode network. An acute administration of stimulants may reduce brain alterations observed in untreated individuals in fronto-striato-parieto-cerebellar networks during tasks or at rest. Potential effects of prolonged treatment remain controversial. Overall, neuroimaging has fostered understanding on stimulant mechanism of action. However, studies are often limited by small samples, short or no follow-up, and methodological heterogeneity. Future studies should address age-related and longer-term effects, potential differences among stimulants, and predictors of treatment response.
摘要：
兴奋剂代表注意力缺陷/多动症（ADHD）的一线药物治疗，是处方最多的精神药理学治疗方法之一。它们在突触水平上的作用机制已被广泛研究。然而,尚不清楚它们的作用机制如何决定临床观察到的益处.为了帮助弥合这个差距，我们提供了对兴奋剂作用的全面审查，重点是核医学和磁共振成像（MRI）的发现。有证据表明，兴奋剂诱导的多巴胺和去甲肾上腺素神经传递的调节优化了与任务相关的大脑网络的参与，增加感知的显著性，并减少来自默认模式网络的干扰。在任务或休息期间，急性服用兴奋剂可能会减少未经治疗的个体在前纹状体-底小脑网络中观察到的大脑变化。长期治疗的潜在影响仍存在争议。总的来说,神经影像学促进了对兴奋剂作用机制的理解。然而,研究通常受到小样本的限制，短期或无后续行动，和方法论的异质性。未来的研究应该解决与年龄相关的长期影响，兴奋剂之间的潜在差异，和治疗反应的预测因子。
