Neuropsychological Effects of Placebo Stimulants in College Students

The past 15 years has seen increases in the nonmedical use of prescription stimulants (NMUPS; e.g., Adderall, Ritalin, Focalin) across college students with rates reported between 6 and 34 percent. Many underestimate or ignore the serious side effects associated with stimulant medication. Furthermore, stimulant medications used to treat ADHD are classified as Schedule II drugs by the Drug Enforcement Agency as they provide beneficial outcomes when used as a prescription medication, but have a high potential risk for abuse, rendering the diversion and unprescribed use illegal. There is also the ethical dilemma that arises when students have access to prescription stimulants to use nonmedically for the purpose of cognitive enhancement. The present study measured the effect a placebo stimulant and one’s personal expectancies have on subjective physiological changes and academic enhancement.

Undergraduate college students (N = 305) participated in a two-phase study. Phase I involved completing an online survey to gather distal study variables and screen participants for medical exclusionary criteria that precludes them from obtaining a stimulant prescription. Phase II required students to attend an in-person session in which they completed various physiological and neuropsychological measures (e.g., Physical Symptom Checklist, Digit Span, Passage Comprehension). Students were randomized to receive 30 milligrams of a placebo stimulant medication (experimental) or no medication (control). Following a 30-minute absorption period, participants completed another set of physiological and neuropsychological measures. A repeated measures-MANCOVA revealed no significant differences between groups from time 1 to 2 despite positive symptom changes in the experimental group. Expectancies moderated performance on some neuropsychological tasks. Future research should include more participants with a history of NMUPS and stimulant medication in addition to placebo.