Healthy
Conditions
Keywords
Methylphenidate, Effortful Control, Attention Control, Cognitive functions
Brief summary
Effortful control refers to the mental processes that help a person to regulate his or her own attention, thoughts, and emotions. This study will examine behavioral differences in healthy individuals when performing a task that induces fatigue. The purpose of this study is to examine the effects of methylphenidate on the cognitive functions in healthy individuals when performing fatiguing cognitive tasks.
Detailed description
Based on the multi-source interference task, all subjects' cognitive functions will be assessed based on reaction time, reaction variability, and accuracy of performance on the attention control task. This study aims to recruit 120 total healthy participants. Overall Safety Plan Subject Protections and Safety Monitoring 1. Confidentiality of records is assured by assigning the subjects research numbers and storing computer files without reference to name, except for a single linking file that links subject's names with their research numbers. Paper records are kept in locked file drawers in a locked room, to which only authorized research personnel have access. When the study is completed, the linking file that links subject's names with their research numbers will be permanently destroyed. 2. Furthermore, upon the event of a subject's participation being terminated, all information collected prior to the subject being removed from the study, will be destroyed. 3. Personnel involved in the study are acutely sensitive to people's unease about revealing personal information. Research personnel also take the required Program for Education and Evaluation in Responsible Research and Scholarship certification, and take the utmost precautions about protecting confidentiality. When potential subject voices their lack of interest in participating, all identifying information is destroyed. During the study, subjects are reminded that they do not have to answer questions that make them feel uncomfortable i. Data Safety and Monitoring Plan 1. No subjects will be recruited or run until the protocol receives full review and approval by the Medical IRB at the University of Michigan. A clinical research associate will accompany all subjects throughout the study. Any minor anxiety arising during the course of the procedures will be immediately assessed, and typically managed with reassurance and simple relaxation techniques. Assessment will always include an evaluation of the subject's ability to continue in the protocol. 2. All subjects will be fully informed of all the possible side-effects that could be encountered during the study. Every measure will be taken to protect subjects against even the rarest possible side effects. Principal Investigator, Dr. Chandra Sripada, has extensive prior experience with methylphenidate and the challenges utilized in this study. 3. Subjects will be encouraged to contact the investigator if they notice any symptoms or untoward side effects. All subjects will have direct access to the phone numbers and pagers of the study coordinator and the responsible physician (Dr. Sripada), as well as a 24-hour contact number (emergency room services). This information is included in the copy of the consent forms provided to the subjects. ii. Reporting of adverse events Adverse events (AEs) will be recorded and tracked for these projects. Adverse events will be reported per IRBs, FDA, and NIH guidelines. An adverse event is any experience that has taken place during the course of a research project, which, in the opinion of the investigators, was harmful to a subject participating in the research, increased the risks of harm in the research, or had an unfavorable impact on the risk/benefit ratio. Adverse events will be graded using the mild, moderate, severe terminology as defined: * Mild - Noticeable to the subject, does not interfere with the subject's daily activities, usually does not require additional therapy, dose reduction, or discontinuation of the study. * Moderate - Interferes with the subject's daily activities, possibly requires additional therapy, but does not require discontinuation of the study. * Severe - Severely limits the subject's daily activities and may require discontinuation of the study. This would include all adverse events defined as Serious by the IRBMED. The PI will assign attribution as definitely associated, probably associated, possibly associated, or unrelated. Adverse events will also be recorded as expected or unexpected. All Serious AEs and/or unexpected AEs will be reported to the IRB, NIH, and the FDA, within 7 days of occurrence or recognition. Fatal or life-threatening adverse events will be reported to the above institutions within 24 hours. Regular annual reviews of protocol activity and all adverse events will be submitted to the IRBs and NIH. Other less serious and expected AEs will also be reported to the above institutions with compliance to their requirements. iii. Persons responsible Chandra Sekhar Sripada and Project Coordinator Christina Bohensky will be responsible for overseeing data integrity, safety monitoring, and reporting of adverse events. During the phone conferences and semi -annual meetings adverse events, recruitment, data quality and integrity and compliance with protocols will be discussed as well. VI. Data Analysis Regression analysis will be utilized to assess whether the dependent measures for the tasks (accuracy, reaction time) are significantly correlated with measures of trait impulsivity derived from the Barratt Impulsivity Scale-11 questionnaire. Independent samples t-tests will be used to determine whether task performance differs due to methylphenidate versus placebo administration.
Interventions
20 mgs of methylphenidate or placebo to be administered one hour before task performance
20 mgs of methylphenidate or a placebo to be administered one hour before task performance
Subjects do an easy version of the Letter E Task.
Subjects do a hard version of the Letter E Task.
Sponsors
Study design
Eligibility
Inclusion criteria
* Age range 18-35
Exclusion criteria
* Pregnant or nursing (females) * Any clinically significant medical condition * Currently taking any medications (i.e., decongestants) * Currently taking any psychoactive medications * Alcohol or substance abuse (current or in the past 2 years) * Liver or Kidney disease * Any clinically significant personal or family history of cardiac problems
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Reaction Time on the Multi-Source Interference Task | 20-30 minutes for task completion | Reaction time on the Multi-Source Interference Task is measured in milliseconds. Participants were given 200 trials and their mean reaction time was calculated. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Accuracy on the Multi-Source Interference Task. | 20-30 minutes | Patients completed 200 trials and the percentage of answers correct was calculated. |
| Reaction Time Variability on the Multi-Source Interference Task. | 20-30 minutes | Reaction time variability on the Multi-Source Interference task is defined as the number of milliseconds between an individual's lowest and highest reaction time. This is averaged across all participants. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Placebo Easy Healthy participants are given a placebo (sugar pill) one hour before task performance and complete an easy version of the Letter E task. | 27 |
| Placebo Hard Healthy participants are given 20 mgs of Methylphenidate one hour before task performance and complete a hard version of the Letter E task. | 27 |
| Methylphenidate Easy Healthy participants are given 20 mgs of Methylphenidate one hour before task performance and complete an easy version of the Letter E task. | 27 |
| Methylphenidate Hard Healthy participants are given 20 mgs of Methylphenidate one hour before task performance and complete a hard version of the Letter E task. | 27 |
| Total | 108 |
Baseline characteristics
| Characteristic | Placebo Hard | Methylphenidate Easy | Placebo Easy | Methylphenidate Hard | Total |
|---|---|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 23 Participants | 23 Participants | 24 Participants | 24 Participants | 94 Participants |
| Age, Continuous | 25.8 years STANDARD_DEVIATION 2 | 26.9 years STANDARD_DEVIATION 4.3 | 28.2 years STANDARD_DEVIATION 4.8 | 26.6 years STANDARD_DEVIATION 3.4 | 26.9 years STANDARD_DEVIATION 3.8 |
| Region of Enrollment United States | 23 Participants | 23 Participants | 24 Participants | 24 Participants | 94 Participants |
| Sex: Female, Male Female | 15 Participants | 14 Participants | 17 Participants | 13 Participants | 59 Participants |
| Sex: Female, Male Male | 8 Participants | 9 Participants | 7 Participants | 11 Participants | 35 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk |
|---|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 27 | 0 / 27 | 0 / 27 | 0 / 27 |
| other Total, other adverse events | 0 / 27 | 0 / 27 | 0 / 27 | 0 / 27 |
| serious Total, serious adverse events | 0 / 27 | 0 / 27 | 0 / 27 | 0 / 27 |
Outcome results
Reaction Time on the Multi-Source Interference Task
Reaction time on the Multi-Source Interference Task is measured in milliseconds. Participants were given 200 trials and their mean reaction time was calculated.
Time frame: 20-30 minutes for task completion
Population: Participants whose accuracy on task one fell below 80% or who were greater than two standard deviation outliers in reaction time were excluded from analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Placebo Easy | Reaction Time on the Multi-Source Interference Task | 300 milliseconds | Standard Deviation 70 |
| Placebo Hard | Reaction Time on the Multi-Source Interference Task | 330 milliseconds | Standard Deviation 90 |
| Methylphenidate Easy | Reaction Time on the Multi-Source Interference Task | 310 milliseconds | Standard Deviation 80 |
| Methylphenidate Hard | Reaction Time on the Multi-Source Interference Task | 280 milliseconds | Standard Deviation 70 |
Accuracy on the Multi-Source Interference Task.
Patients completed 200 trials and the percentage of answers correct was calculated.
Time frame: 20-30 minutes
Population: Participants whose accuracy on task one fell below 80% or who were greater than two standard deviation outliers in reaction time were excluded from analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Placebo Easy | Accuracy on the Multi-Source Interference Task. | 94.1 percentage of answers which were correct | Standard Deviation 3.5 |
| Placebo Hard | Accuracy on the Multi-Source Interference Task. | 94.3 percentage of answers which were correct | Standard Deviation 5.3 |
| Methylphenidate Easy | Accuracy on the Multi-Source Interference Task. | 96.1 percentage of answers which were correct | Standard Deviation 3.2 |
| Methylphenidate Hard | Accuracy on the Multi-Source Interference Task. | 96.6 percentage of answers which were correct | Standard Deviation 3.2 |
Reaction Time Variability on the Multi-Source Interference Task.
Reaction time variability on the Multi-Source Interference task is defined as the number of milliseconds between an individual's lowest and highest reaction time. This is averaged across all participants.
Time frame: 20-30 minutes
Population: Participants whose accuracy on task one fell below 80% or who were greater than two standard deviation outliers in reaction time were excluded from analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Placebo Easy | Reaction Time Variability on the Multi-Source Interference Task. | 270 milliseconds | Standard Deviation 50 |
| Placebo Hard | Reaction Time Variability on the Multi-Source Interference Task. | 320 milliseconds | Standard Deviation 70 |
| Methylphenidate Easy | Reaction Time Variability on the Multi-Source Interference Task. | 270 milliseconds | Standard Deviation 70 |
| Methylphenidate Hard | Reaction Time Variability on the Multi-Source Interference Task. | 260 milliseconds | Standard Deviation 40 |