Objective and subjective cognitive enhancing effects of mixed amphetamine salts in healthy people.
Level 2 - randomized trial
Double-blind cross-over placebo-controlled randomized trial
PubMed 22884611 · doi:10.1016/j.neuropharm.2012.07.021
What was done
Healthy young adults participated in a double-blind, cross-over, placebo-controlled trial assessing the effects of mixed amphetamine salts (MAS; Adderall). Investigators evaluated 13 cognitive measures spanning episodic memory, working memory, inhibitory control, convergent creativity, intelligence, and scholastic achievement. The study tested for general enhancement effects (defined as Cohen's d >= 0.5), moderation by baseline cognitive ability or COMT genotype, and subjective perceptions of performance enhancement.
What was found
The abstract reports no numerical test scores, effect sizes, or participant counts. Overall, MAS did not produce cognitive enhancement across participants. A minority of tasks showed potential moderation by baseline ability and COMT genotype, with lower-ability participants showing enhancement on word recall, embedded figures, and Raven's Progressive Matrices. Despite the absence of objective enhancement across most tasks and participants, subjects perceived their performance to be more enhanced on the active drug compared to placebo.
Why it matters
This trial directly challenges the widespread assumption that prescription psychostimulants reliably boost objective cognitive capability in healthy individuals, highlighting a disconnect where users experience an illusion of enhancement without measurable gains.
Limits
The abstract omits the sample size, specific drug dosages, participant demographics, and numerical statistical values. Findings reflect acute laboratory testing in healthy young adults and cannot be generalized to clinical populations with ADHD, long-term repeated use, or broader real-world performance tasks.