ADHD
Conditions
Brief summary
To investigate the effects of methylphenidate on motivated behavior in adults with and without ADHD
Detailed description
This study has a mixed between- and within-subject design. Participants are young adults (aged 18-45) with ADHD and non-ADHD matched controls. They will be recruited from locations around the community, consented, screened for eligibility, then scheduled for 2 study days. Study days will be at least 48 hours apart. Thus, there will be a total of 3 lab visits across a 3 week period. Participants will be administered study drug on one study day and placebo on the other study day. They will complete a battery of cognitive/behavioral tasks and answer questionnaires on both study days.
Interventions
DRUGADHD methylphenidate first, placebo second
double-blind, counter-balanced administration
DRUGADHD placebo first, methylphenidate second
double-blind, counter-balanced administration
DRUGNon-ADHD methylphenidate first, placebo second
double-blind, counter-balanced administration
DRUGNon-ADHD placebo first, methylphenidate second
Sponsors
University of Arkansas
Study design
Allocation
NON_RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Investigator)
Intervention model description
There are two parallel arms of this study (ADHD or non-ADHD subjects). Within each arm, each subject will be exposed to placebo and a drug (each at a different timepoint in the study). Although all subjects will receive both placebo and the drug, the order of presentation of the placebo and drug is counterbalanced across subjects (i.e., approximately half will receive the drug first and approximately half will receive the placebo first). For both study arms, regardless of whether the placebo is received first or second, the outcome measure will be calculated as the number of high effort selections.
Eligibility
Sex/Gender
ALL
Age
18 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
1. generally healthy 2. between the ages of 18-45 3. non-ADHD subjects do not meet criteria for ADHD diagnosis or any subtype as determined by the Conners Diagnostic Interview or any T-Score \> 55 on Inattentive Symptoms, Hyperactive-Impulsive Symptoms, Total Symptoms or ADHD Index subscales of the CAARS. 4. ADHD subjects meet criteria for a primary diagnosis of ADHD, any subtype, based on DSM-5
Exclusion criteria
1. inability to attend all required experimental sessions 2. significant health problems (e.g., current and uncontrolled liver, lung, or heart problems, current or past seizure disorder, serious head trauma) 3. primary diagnosis of Axis I psychiatric disorders other than ADHD (e.g., depression, anxiety disorder, schizophrenia) 4. meet DSM-5 criteria for substance use disorder other than nicotine in the past 12 months 5. use of psychoactive medications in the past 6 months as indicated by self-report 6. positive urine drug screen for drugs or positive breath alcohol concentration 7. contraindications for MPH 8. among women, nursing or a positive pregnancy test 9. IQ \< 80 on Kaufman Brief Intelligence Test, 2nd edition 10. allergy to lactose 11. hypertension (If subject is ≤ 40 years of age and has blood pressure over 135/85 or heart rate over 90 beats per minute. If subject is \> 40 years of age and has blood pressure over 130/80 or heart rate over 88 beats per minute) 12. body mass ratio \> 30
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Number of High-effort Selections in the Effort-based Decision Making Task | 1 hour post drug (or placebo) administration for each study session | Number of high-effort selections in the effort-based decision making task from the placebo to the methylphenidate condition. This is a decision-making task where participants make high- or low-effort choices to earn a small financial reward. High-effort selections require 100 button presses with non-dominant hand pinky finger and low-effort selections require 30 button presses with dominant hand index finger (within 15 seconds). The number of high effort selections are summed across 50 trials of the task. This task measures the willingness to perform effort in relation to changing reward magnitude and probability. This is a basic science experiment, the clinical and/or physiological relevance of these results are not established. |
Countries
United States
Participant flow
Recruitment details
Within each study arm (ADHD or non-ADHD subjects), subjects were exposed to placebo and drug (each at a different timepoint in the study). Approximately half of the subjects within each arm received drug first and half received placebo first (i.e., order was counterbalanced).
Participants by arm
| Arm | Count |
|---|---|
| ADHD Adults with ADHD | 23 |
| Non-ADHD Adults without ADHD | 23 |
| Total | 46 |
Baseline characteristics
| Characteristic | Total | ADHD | Non-ADHD |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 46 Participants | 23 Participants | 23 Participants |
| Age, Continuous | 31 years STANDARD_DEVIATION 8 | 33 years STANDARD_DEVIATION 8 | 28 years STANDARD_DEVIATION 7 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 7 Participants | 0 Participants | 7 Participants |
| Race (NIH/OMB) More than one race | 9 Participants | 5 Participants | 4 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 30 Participants | 18 Participants | 12 Participants |
| Region of Enrollment United States | 46 participants | 23 participants | 23 participants |
| Sex: Female, Male Female | 24 Participants | 12 Participants | 12 Participants |
| Sex: Female, Male Male | 22 Participants | 11 Participants | 11 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 / 12 | 0 / 11 | 0 / 11 | 0 / 12 |
| other Total, other adverse events | 0 / 12 | 0 / 11 | 0 / 11 | 0 / 12 |
| serious Total, serious adverse events | 0 / 12 | 0 / 11 | 0 / 11 | 0 / 12 |
Outcome results
Primary
Number of High-effort Selections in the Effort-based Decision Making Task
Number of high-effort selections in the effort-based decision making task from the placebo to the methylphenidate condition. This is a decision-making task where participants make high- or low-effort choices to earn a small financial reward. High-effort selections require 100 button presses with non-dominant hand pinky finger and low-effort selections require 30 button presses with dominant hand index finger (within 15 seconds). The number of high effort selections are summed across 50 trials of the task. This task measures the willingness to perform effort in relation to changing reward magnitude and probability. This is a basic science experiment, the clinical and/or physiological relevance of these results are not established.
Time frame: 1 hour post drug (or placebo) administration for each study session
Population: Approximately half of the subjects within each arm (ADHD or non-ADHD) received drug first and half received placebo first (i.e., order was counterbalanced). The study was powered to compare two groups (ADHD vs non-ADHD). Since order of drug was counterbalanced, this means all ADHD subjects were evaluated under both placebo and drug conditions, and this is also true for the non-ADHD subjects.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| ADHD Subjects, Placebo Condition | Number of High-effort Selections in the Effort-based Decision Making Task | 16.4 Number of high-effort selections | Standard Error 2.2 |
| ADHD Subjects, Methylphenidate Condition | Number of High-effort Selections in the Effort-based Decision Making Task | 21.35 Number of high-effort selections | Standard Error 1.9 |
| Non-ADHD Subjects, Placebo Condition | Number of High-effort Selections in the Effort-based Decision Making Task | 20.45 Number of high-effort selections | Standard Error 2.2 |
| Non-ADHD Subjects, Methylphenidate Condition | Number of High-effort Selections in the Effort-based Decision Making Task | 19.8 Number of high-effort selections | Standard Error 1.9 |