Did not receive funding

We propose to evaluate the interaction between expectations of receiving stimulants, neurophysiological activity and enhancement of cognitive performance using fMRI.

Participants will then be randomized in a balanced placebo design (BPD) crossing medication (10 mg of mixed amphetamine salts vs placebo) and expectancy (told active medication vs placebo medication), resulting in 4 different conditions 1) mixed amphetamine salts/told stimulant medication; 2) placebo/told stimulant medication; 3) mixed amphetamine salts/told placebo; and 4) placebo/told placebo). Participants will be assigned to four scanning sessions scheduled one week apart and will experience each condition once counterbalanced across participants. Participants will be administered cognitive tasks in and out of the scanner to determine the effects of medication vs expectancy.

Inclusion Criteria:

• 18-30 years old
• enrolled as a student at UAB or local college/university
• if female, willing to use adequate birth control or abstain from sexual activity

Exclusion Criteria:

• current or prior head injury
• current or prior psychiatric diagnosis (including ADHD)
• neurological disorder or stroke, hypertension, history of blood or circulation disorders (e.g., anemia or sickle-cell), diabetes, brain or spinal abnormalities
• blood pressure more than 130 systolic and 80 diastolic
• heart rate more than 100 beats per minute
• pregnancy
• current illicit substance use as well as nicotine use
• Alcohol or cannabis use that meets DSM-5 criteria for an alcohol or cannabis use disorder
• Inability to abstain from alcohol or cannabis the night before and day of the scanning session
• Inability to reduce caffeine intake to less than 100 mg on testing days in heavy caffeine users
• claustrophobia
• hearing impairment
• vision impairment that cannot be corrected by MRI-compatible lenses

This will be a double-blind study. Research assistants will administer capsules, and based on package labeling, tell the participant if they are being administered Adderall or placebo. However, researchers and participants will be blind to which medication is actually being administered.