tDCS for Inhibitory Control Deficits: A Test in OCD

描述(申请人提供)：缺乏抑制控制是许多精神障碍的中心特征，包括注意缺陷多动障碍，药物滥用和依赖，以及强迫症(OCD)。到目前为止，还没有广泛针对抑制性控制缺陷的既定干预措施，尽管这一行为维度与一系列障碍有关。经颅直流电刺激(TDC)是一种微弱的、非侵入性的脑刺激，已被发现在右额下回(RIFG)上应用时，在实验室测试和跨行为训练期间可以改善健康人的抑制控制。我们的长期目标是充分利用反应控制神经基础上的成熟文献，并将这些发现推广到健康人群中，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的新型干预方法。 在行为抑制问题以强迫症为特征的临床人群中加强抑制控制。在本研究中，32名患有强迫症的参与者将被随机分成两组，分别接受通过rIFG进行的积极或虚假的tdcs，并结合暴露和反应预防(Erp)进行10次治疗。事件相关电位是治疗强迫症的一线行为疗法，它在很大程度上依赖于对强迫症相关行为的抑制。鉴于行为抑制问题是强迫症的一个标志，而事件相关电位严重依赖于成功的抑制控制，我们预计，将tDCS与事件相关电位结合起来加强抑制控制，最终将导致治疗结果的疗效和/或效率的提高。考虑到这一长期目标，我们设立R21探索性/开发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可以耐受这种ERP+tdcs的联合治疗方法，并将根据招募、治疗完成率和自我报告的比率来确定它是可以接受的。我们的第二个目标是收集证据，证明tdcs作为ERP的辅助治疗强迫症的初步疗效优于rifg。我们假设，在10个疗程的联合治疗中，接受erp+活动tdcs的患者的症状严重程度将比接受erp+sham tdcs的患者表现出更大的缓解。最后，我们将使用传统的实验室抑制控制措施以及与强迫症相关的表面有效、临床相关的抑制控制措施来表征抑制控制措施与联合干预结果之间的关系。为此，我们假设，通过停止信号任务衡量的反应抑制在erp加活动tdcs与假tdcs相比将得到更多改善；强迫症严重性的改善将对应于对停止信号任务的更好的抑制控制；患者接受 与接受ERP加假tdcs训练的受试者相比，在视觉模拟尺度上进行erp训练时，接受erp加主动tdcs训练的受试者报告抑制强迫反应的难度较小。

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.