tDCS for Inhibitory Control Deficits: A Test in OCD

描述（由申请人提供）：抑制控制缺陷是许多精神障碍的中心特征，包括注意缺陷多动障碍、物质滥用和依赖以及强迫症（OCD）.到目前为止，还没有建立广泛针对抑制控制缺陷的干预措施，尽管这种行为维度与一系列疾病相关。经颅直流电刺激（tDCS）是一种弱的非侵入性脑刺激，已被发现在实验室测试期间和在右额下回（rIFG）上应用时，可以改善健康个体的抑制控制。我们的长期目标是利用反应控制的神经基础上的文献，并将这些发现扩展到健康人群中，以便为行为抑制缺陷的临床人群开发更有效的治疗方法。本项目将研究一种使用tDCS的新干预方法， 在一个以行为抑制为特征的临床人群中增强抑制控制：强迫症。在本研究中，32名患有OCD的参与者将被随机分组，接受活性或假tDCS + rIFG，联合暴露和反应预防（ERP）治疗10个疗程。ERP是强迫症的一线行为疗法，其严重依赖于强迫症相关行为的抑制（即，强迫）。考虑到行为抑制问题是强迫症的标志，并且ERP在很大程度上依赖于成功的抑制控制，我们预计用tDCS与ERP组合来增强抑制控制将最终导致治疗结果的功效和/或效率的改善。考虑到这一长期目标，我们对这项R21探索性/发展性研究补助金的主要目的是建立研究程序和临床干预的可行性和可接受性。我们假设，强迫症患者将容忍这种联合ERP + tDCS治疗方法，并会发现它是可以接受的，如招募率，治疗完成率和自我报告。我们的第二个目的是收集tDCS作为ERP辅助治疗强迫症的初步疗效优于rIFG的证据。我们假设接受ERP +活性tDCS的患者在10次联合治疗中的症状严重程度比接受ERP +假tDCS的患者降低更大。最后，我们的目标是表征抑制控制措施和联合干预的结果之间的关系，使用传统的实验室抑制控制措施，以及一个面对有效的，临床相关的措施，强迫症相关的抑制控制。为此，我们假设，通过停止信号任务测量的反应抑制，在ERP加活性tDCS与假tDCS之后将改善更多; OCD严重程度的改善将对应于停止信号任务的抑制控制的改善;并且接受 在视觉模拟量表上，ERP加主动tDCS在ERP练习期间比接受ERP加假tDCS的人报告抑制强迫的难度更小。

DESCRIPTION (provided by applicant): Deficient inhibitory control is a central feature of numerous mental disorders, including attention deficit hyperactivity disorder, substance abuse and dependence, and obsessive- compulsive disorder (OCD). As of yet, there are no established interventions broadly targeting deficits in inhibitory control, despite the relevance o this behavioral dimension to a range of disorders. Transcranial direct current stimulation (tDCS), a type of weak, noninvasive brain stimulation, has been found to improve inhibitory control in healthy individuals during laboratory tests and across behavioral training sessions when applied over the right inferior frontal gyrus (rIFG). Our long-term goal is to leverage a well-developed body of literature on the neural basis of response control and extend these findings in healthy populations in order to develop more effective treatment approaches for clinical populations with deficits in behavioral inhibition. This project will investigate a novel intervention using tDCS to enhance inhibitory control in one clinical population where problems with behavioral inhibition characterize the disorder: OCD. In the present study, 32 participants with OCD will be urn randomized to receive either active or sham tDCS over rIFG, delivered over 10 sessions in combination with exposure and response prevention (ERP). ERP is a first-line behavioral therapy for OCD which relies heavily on inhibition of OCD-related behaviors (i.e., compulsions). Given that problems with behavioral inhibition are a hallmark of OCD and that ERP relies heavily on successful inhibitory control, we expect that enhancing inhibitory control with tDCS in combination with ERP will ultimately lead to improved efficacy and/or efficiency of treatment outcomes. With this long-term objective in mind, our primary aim for this R21 Exploratory/Developmental Research Grant is to establish feasibility and acceptability of the research procedures and clinical intervention. We hypothesize that OCD patients will tolerate this combined ERP + tDCS treatment approach and will find it acceptable, as determined by rates of recruitment, treatment completion, and self-report. Our secondary aim is to gather evidence on preliminary efficacy of tDCS over rIFG as an adjunct to ERP for OCD. We hypothesize that patients in the group receiving ERP + active tDCS will show greater reduction in symptom severity over 10 sessions of the combined treatment than those receiving ERP + sham tDCS. Finally, we will aim to characterize the relationship between measures of inhibitory control and outcome of the combined intervention, using a traditional laboratory measure of inhibitory control as well as a face-valid, clinically relevant measure of OCD-related inhibitory control. For this aim, we hypothesize that response inhibition, as measured by the stop signal task, will improve more after ERP plus active vs. sham tDCS; that improvement in OCD severity will correspond to improved inhibitory control on the stop signal task; and that patients receiving ERP plus active tDCS will report less difficulty inhibiting compulsions during ERP exercises on a visual analog scale than those receiving ERP plus sham tDCS.