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Stimulant Effects on Brain Activity

2015年5月22日 更新者:Russell Schachar、The Hospital for Sick Children

Stimulant Effects on Brain Activity During the Stop Signal Task

The aim of this study is to investigate the effects of Methylphenidate on neural activity underlying inhibitory control and error monitoring in healthy adults. More specifically, the investigators aim to establish the baseline modulatory effect of Mehtlylphenidate on bottom-up and top-down aspects of these cognitive processes. This work will further our understanding of Attention Deficit Hyperactivity Disorder, Methylphenidate, and executive functioning.

研究概览

详细说明

Methylphenidate (MPH) is the stimulant medication most commonly used in the treatment of attention deficit hyperactivity disorder (ADHD). MPH suppresses the reuptake of dopamine by blocking dopamine transporter, which is elevated in ADHD. However, the precise mechanism by which suppressed dopamine transporter activity relieves ADHD symptoms is not fully understood, partly because dopamine pathways are implicated in various processes that could play a role in the deficits of ADHD and other disorders. MPH-induced dopamine variation has extensive effects in the brain and influences various executive functions in unknown ways.

Hypotheses:

Inhibitory Control: The investigators predict that MPH should increase the top-down activity in right dorsolateral prefrontal cortex associated with response restraint during go-phases and bottom-up activity in caudate and right inferior frontal cortex associated with response cancellation during successful stop trials. A greater modulation of top-down or bottom-up activity would imply a selective effect of MPH on one pathway over the other.

Error Processing: The investigators predict that MPH should increase the intensity of deactivation in the bottom-up dopamine pathway on error detection (substantia nigra, dorsal striatum and ACC), and increase the intensity of deactivation in the top-down pathway on post-error slowing (caudal OFC, ventral striatum, ventral substantia nigra). A greater modulation of top-down or bottom-up activity would imply a selective effect of MPH on one pathway over the other.

研究类型

介入性

注册 (实际的)

19

阶段

  • 阶段1

联系人和位置

本节提供了进行研究的人员的详细联系信息,以及有关进行该研究的地点的信息。

学习地点

    • Ontario
      • Toronto、Ontario、加拿大、M5G 1X8
        • The Hospital for Sick Children

参与标准

研究人员寻找符合特定描述的人,称为资格标准。这些标准的一些例子是一个人的一般健康状况或先前的治疗。

资格标准

适合学习的年龄

18年 至 35年 (成人)

接受健康志愿者

是的

有资格学习的性别

男性

描述

Inclusion Criteria

  • Healthy, non-smoking, male and female volunteers, between 18 to 35 years of age inclusive, right-handed
  • Body Mass Index that is within 18.5-29.9 kg/m2, inclusive
  • Healthy, according to the medical history, vital signs, and physical examination (within 2 years prior to study enrollment)
  • Systolic blood pressure between 100-140 mmHg, inclusive, and diastolic blood pressure between 60-90 mmHg, inclusive, and heart rate between 50-100 bpm, inclusive, unless deemed not clinically significant by the Principal Investigator/ Sub-Investigator?
  • Capable of giving written informed consent prior to receiving any study medication
  • Female subjects must fulfill at least one of the following:

    • Agree to avoid pregnancy and use medically acceptable method of contraception from at least 30 days prior to the study, during the study, and until 30 days after the study has ended (last study procedure). Medically acceptable methods of contraception include oral contraceptives, hormonal patch, implant or injection intrauterine device, or double barrier method (condom with foam or vaginal spermicidal suppository, diaphragm with spermicide). Complete abstinence alone can be used as a method of contraception.
    • Be surgically sterile for a minimum of 6 months
    • Post-menopausal for a minimum of 1 year

Exclusion Criteria

  • Known history or presence of any clinically significant hepatic (e.g. hepatic necrosis, jaundice, hepatobiliary disease), renal, gastrointestinal (e.g. peptic ulcer), cardiovascular (e.g. angina, myocardial infarction), cerebrovascular, pulmonary, endocrine (e.g. diabetes, hypophosphatemia), immunological, musculoskeletal (e.g. rhabdomyolysis, myopathy), neurological, psychiatric, dermatological, or hematological disease or condition
  • Presence of any clinically significant illness within 30 days prior to dosing
  • Presence of any significant physical or organ abnormality
  • Known history or presence of:

    • Alcohol abuse or dependence within one year prior to drug administration
    • Drug abuse or dependence
    • Hypersensitivity to methylphenidate or other medications
    • Gout
    • Food allergies and/or presence of any dietary restrictions
    • Severe allergic reactions (e.g. anaphylactic reactions, angioedema)
  • Participation in another clinical trial or receiving an investigational drug within 30 days of the study commencement or during the study
  • Use of any prescription medication within 14 days prior to drug administration (except for hormonal contraceptives)
  • Use of any over-the-counter medications (including herbal and/or dietary supplements and/or teas) within 14 days prior to drug administration (except for spermicidal/barrier contraceptive products)
  • Any major surgery within 6 months prior to the start of the study
  • Pregnant or lactating
  • Lactose intolerance
  • Contraindication for MRI (using hospital's standard screening procedure)
  • Smoking

学习计划

本节提供研究计划的详细信息,包括研究的设计方式和研究的衡量标准。

研究是如何设计的?

设计细节

  • 主要用途:诊断
  • 分配:随机化
  • 介入模型:交叉作业
  • 屏蔽:双倍的

武器和干预

参与者组/臂
干预/治疗
安慰剂比较:控制组
Lactose Placebo
实验性的:哌醋甲酯
oral dose of methylphenidate. The MPH dose was selected based on previous studies in healthy adults (Mehta et al., 2000; Volkow, Fowler, Wang, Ding, & Gatley, 2002) and adults with ADHD (Aron et al., 2003). MPH reaches its peak plasma concentration 1-3 hours after an oral dose, and has a plasma half-life of 1.5-2.5 hours.

研究衡量的是什么?

主要结果指标

结果测量
措施说明
大体时间
Neural activity assessed using fMRI
大体时间:7 days
Assessed using fMRI
7 days

合作者和调查者

在这里您可以找到参与这项研究的人员和组织。

调查人员

  • 首席研究员:Russell Schachar, MD、The Hospital for Sick Children, Toronto Canada

研究记录日期

这些日期跟踪向 ClinicalTrials.gov 提交研究记录和摘要结果的进度。研究记录和报告的结果由国家医学图书馆 (NLM) 审查,以确保它们在发布到公共网站之前符合特定的质量控制标准。

研究主要日期

学习开始

2011年1月1日

初级完成 (实际的)

2012年1月1日

研究完成 (实际的)

2012年3月1日

研究注册日期

首次提交

2015年5月21日

首先提交符合 QC 标准的

2015年5月22日

首次发布 (估计)

2015年5月25日

研究记录更新

最后更新发布 (估计)

2015年5月25日

上次提交的符合 QC 标准的更新

2015年5月22日

最后验证

2015年5月1日

更多信息

此信息直接从 clinicaltrials.gov 网站检索,没有任何更改。如果您有任何更改、删除或更新研究详细信息的请求,请联系 register@clinicaltrials.gov. clinicaltrials.gov 上实施更改,我们的网站上也会自动更新.

Methylphenidate的临床试验

3
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