Acute Effects of Prescription Stimulant Medication on Cognition and Mood in College Students With and Without ADHD
Overview
- Phase
- Phase 2
- Intervention
- Adderall IR 10mg
- Conditions
- Attention Deficit Hyperactivity Disorder
- Sponsor
- University of Wyoming
- Enrollment
- 40
- Locations
- 1
- Primary Endpoint
- Change in Continuous Performance Test - Identical Pairs (CPT-IP) for Adderall vs. Placebo
- Status
- Recruiting
- Last Updated
- last year
Overview
Brief Summary
The investigators will examine the acute effects of stimulant medication on executive functioning. The rationale for the proposed study is to examine the efficacy of stimulants for college students with ADHD and help prevent stimulant misuse among college students without ADHD. The working hypothesis is that stimulants, compared to baseline and placebo conditions, will improve executive functioning for college students with ADHD but not for college students without ADHD. Improvements on executive functioning measures (e.g., CPT-IP, Spatial Span) will be examined through 2 (ADHD vs. non-ADHD) x 3 (Baseline, Placebo, Stimulant) repeated measures ANOVAs. Follow-up analyses will include paired comparisons.
Expected outcomes are to confirm these hypotheses and demonstrate the need for further study of stimulants. If confirmed, the results will provide pilot data for a larger NIH grant proposal aimed at further examining the acute effects of stimulants (i.e., improved cognitive functioning with stimulants) and comparing them to the acute effects of physical exercise (i.e., improved cognitive functioning immediately after exercise). The investigators expect this outcome to have an important positive impact because it can help support stimulant medication as an effective treatment for college students with ADHD (DuPaul et al., 2012). Additionally, demonstration that stimulants do not improve executive functioning for college students without ADHD can be used to help prevent and discourage stimulant misuse and diversion on college campuses (Hartung et al., 2013).
Detailed Description
Participants. The investigators will enroll 40 University of Wyoming (UW) and Laramie County Community College (LCCC) students including 20 with ADHD and 20 without ADHD (20 men, 20 women). Power analyses (G\*Power 3.1; Faul et al., 2007) indicated a sample of at least this size is needed to provide 80% power to detect medium effects. Participants will be recruited through several means including targeted email announcements, flyers, and SONA pre-screener data. Full exclusion criteria can be found in the "Eligibility" section below. Most notably, participants must stratify as being low risk for stimulant medication use. A health history screening questionnaire and additional health items will be used to screen participants and responses will be reviewed and approved by a medical consultant. All prospective participants will attend a baseline appointment to confirm eligibility including: (a) being at low risk for stimulant use contraindications and (b) meeting diagnostic threshold for ADHD. After confirming eligibility, participants will also complete baseline measures during the baseline appointment. After enrolling in the study, participants will be scheduled for two experimental appointments. The two experimental appointments will include: (a) Placebo pill and (b) Stimulant (Adderall IR 10mg). The ordering of experimental appointments will be counterbalanced. Experimental appointments will be scheduled in the mornings and on the same day of the week and same time of day. Participants will be asked to abstain from caffeine, alcohol, nicotine, and illicit drugs for 12 hours prior to their appointments. Participants will be administered either placebo or stimulant. After a 90-minute wait, participants will complete executive functioning measures. Physiological measures (e.g., heart rate and blood pressure) will be monitored at specific times throughout the appointment and a medical consultant will be available on call for any emergencies. Participants will also be sent a modified mood (i.e., Depression, Anxiety, and Stress Scale or DASS) and sleep (Pittsburgh Sleep Quality Index or PSQI) questionnaire the morning following all experimental appointments. The only difference between the two appointments is the administration of either placebo or stimulant. Prior to analyses, all variables will be screened. Violations of statistical assumptions will be addressed through data transformations or nonparametric statistics. Improvements on executive functioning measures (e.g., CPT-IP, Spatial Span) will be examined through 2 (ADHD vs. non-ADHD) x 3 (Baseline, Placebo, Stimulant) repeated measures ANOVAs. When interactions are significant, paired samples t-tests will be used to evaluate group differences. When interaction effects fail to reach statistical significance, independent samples t-tests will be used to evaluate group differences. The magnitude of omnibus effects for repeated measures ANOVAs will be calculated using partial eta-squared (ηp2). Within-group effects (Cohen's d) and corresponding confidence intervals for within-group effect sizes will be standardized using the variability of baseline scores (Howell, 2011). Between-group effects will be calculated using Hedges g (Hedges, 1982).
Investigators
Cynthia M Hartung, PhD
Associate Professor
University of Wyoming
Eligibility Criteria
Inclusion Criteria
- •Be currently enrolled either full time or part time as an undergraduate in a 2-year or 4-year college
- •Be between the ages of 18-29
- •Be a native English speaker
- •ADHD Participants: Must report a prior diagnosis of ADHD and self-report five or more inattention (IA) symptoms on the DSM-5 Symptom Checklist on the pre-screener.
- •Healthy Participants: Must disavow ever being diagnosed with ADHD, report 3 or fewer IA symptoms and 3 or fewer hyperactivity/impulsivity (HI) symptoms on the DSM-5 ADHD Symptom Checklist in the pre-screener and are an age and sex match of an ADHD group participant
Exclusion Criteria
- •Not meeting any of the above stated inclusion criteria
- •Any contraindications for physical exercise placing the participant at moderate or high-risk. This includes the following:
- •Participants will be excluded if they report having an acute or uncontrolled disease (cardiovascular, pulmonary, neurological, endocrine, musculoskeletal, immunological).
- •Participants will be excluded if they are non-ambulatory or rely on walking aids for ambulation.
- •Participants will be excluded who chronically manage asthma or another respiratory condition or require using an inhaler to complete exercise.
- •Participants will be excluded if they experience uncontrolled or current problems with syncope (loss of consciousness or fainting) or postural hypotension.
- •Participants will be excluded if they have ever had a stroke, aneurysm, or transient ischemic attack (TIA).
- •Participants will be excluded if they have exercise or physical activity restrictions imposed by a health provider.
- •Participants will be excluded by the medical director due to possible underlying disease/condition or risk.
- •Participants will be excluded if they are pregnant (determined by a urine pregnancy test), are attempting to become pregnant, or are currently breastfeeding will also be excluded (stated above).
Arms & Interventions
Stimulant Medication
Participants will be administered a stimulant medication (Adderall IR 10mg). The ordering of experimental vs. placebo appointments will be counterbalanced. Participants will complete computer-based tests of sustained attention and working memory during all appointments.
Intervention: Adderall IR 10mg
Stimulant Medication
Participants will be administered a stimulant medication (Adderall IR 10mg). The ordering of experimental vs. placebo appointments will be counterbalanced. Participants will complete computer-based tests of sustained attention and working memory during all appointments.
Intervention: Placebo
Outcomes
Primary Outcomes
Change in Continuous Performance Test - Identical Pairs (CPT-IP) for Adderall vs. Placebo
Time Frame: Completed at baseline and each experimental appointment over a period of three weeks
The CPT-IP is a standardized computer-administered test consisting of four-digit numbers that are presented for 200ms on a white screen with 1500ms between the presentation of each number. Participants must press the spacebar as quickly as possible when the preceding four-digit number matches the current four-digit number. Participants will complete the CPT-IP as a measure of sustained attention at baseline and at each experimental appointment.
Addiction Research Center Inventory (ARCI) for Adderall vs. Placebo
Time Frame: two weeks
The ARCI is a 49 true-false item measure that assesses drug effects by asking how the participant feels in the moment. Participants will complete the ARCI at each experimental appointment.
Change in Spatial Span (SS) for Adderall vs. Placebo
Time Frame: Completed at baseline and each experimental appointment over a period of three weeks
The Spatial Span (SS) is a computer-administered task assessing visuospatial working memory. Participants will be tasked with remembering the order of stimuli that are presented in forward and backward sequences. Participants will complete the SS visuospatial working memory task at baseline and at each experimental appointment.
Change in Letter-Number Sequencing for Adderall vs. Placebo
Time Frame: Completed at baseline and each experimental appointment over a period of three weeks
The Letter-Number Sequencing (Wechsler, 2008) task is a supplemental subtest of the Wechsler Adult Intelligence Scale (WAIS-IV) that measures auditory working memory. Researchers will read a sequence of letters and numbers, and the participant will attempt to recall the numbers in ascending order and the letters in alphabetical order. Participants will complete the Letter-Number Sequencing auditory working memory task at baseline and at each experimental appointment.
Visual Analogue Scales (VAS) for Adderall vs. Placebo
Time Frame: two weeks
The VAS is a nine-item questionnaire that assesses subjective mood in the moment including how good, bad, focused, and motivated participants feel. Additionally, participants are asked how well they expect to perform on cognitive tests and how much effort they will put into completing cognitive tests. Participants will complete the VAS at each experimental appointment.
Intentions to Use Questionnaire (IUQ) for Adderall vs. Placebo
Time Frame: two weeks
The IUQ is a six-item measure that assesses the likelihood of participants to use substances including prescription stimulants for specific purposes such as for studying or improving academic performance. Participants will complete the IUQ at each experimental appointment.
Change in Digit Span for Adderall vs. Placebo
Time Frame: Completed at baseline and each experimental appointment over a period of three weeks
The Digit Span (Wechsler, 2008) subtest of the Wechsler Adult Intelligence Scale (WAIS-IV) is an auditory working memory task. The researcher will say numbers aloud at a rate of one number per second. The participant will be tasked with remembering and repeating the numbers in a prescribed (forward, backward, sequencing) order. Participants will complete the Digit Span (forward, backward and sequencing) auditory working memory task at baseline and at each experimental appointment.
Secondary Outcomes
- Depression, Anxiety, and Stress Scale-Modified (DASS-M)(Completed the day after each experimental appointment over a period of two weeks)
- Side Effects Rating Scale - Modified(Completed the day after each experimental appointment over a period of two weeks)
- Pittsburgh Sleep Quality Index-Modified (PSQI-M)(Completed the day after each experimental appointment over a period of two weeks)
- DSM-5 ADHD Symptoms Checklist - Modified (DSM 5-M)(Completed the day after each experimental appointment over a period of two weeks)
- Substance Use Day After Questionnaire(Completed the day after each experimental appointment over a period of two weeks)