By Emma Young

Stimulants available on prescription such as Adderall improve cognitive functioning as well as attention in people with ADHD, but many students without this condition also take them, believing that they will act as “smart drugs” and boost their cognition, and so their academic performance. The limited research to date into whether this is actually the case has produced mixed results. A new double-blind pilot study of healthy US college students, published in Pharmacy, found that though Adderall led to minor improvements in attention, it actually impaired working memory.

The researchers, from the US and Iceland, recruited 13 healthy college students who were given a 30 mg dose of Adderall in capsule form before one test session, and a placebo capsule before another (adults with ADHD who have been prescribed Adderall take anywhere between 5 and 60 mg per day). The sessions lasted five and a half hours. During this time, the participants completed six neurocognitive tasks (timed to occur when the drug’s effect would be at its peak – between 90 and 210 minutes after taking the capsule). Every half hour, the students also reported how much they were feeling any drug effects and their emotional state, and their heart rate and blood pressure were measured.

The neurocognitive measures assessed working memory, memory for increasingly complex stories, attention and vigilance, memory of past cognition and ability to self-regulate, and also reading. The students also indicated whether they thought the drug had positively or negatively affected their performance on the tests.

The results showed that the drug boosted levels of positive emotion and raised heart rate and blood pressure. It also led to slight improvements on the tests of attention and focus. But it worsened performance on one of the measures of working memory (recall of a string of digits), and also participants’ perceptions of their past cognitive and self-regulation functioning. It had no effect on reading performance.

“While improving attention skills, [Adderall] may simultaneously degrade students’ confidence in their abilities to problem solve, complete tasks and interact with others,” the researchers write.

For the large numbers of students who report taking stimulants, these results suggest that while the drugs might have a slight impact on attention, they probably won’t do much to enhance their academic performance (while Adderall can address a neurocognitive deficit – in people with ADHD – it does not seem to lead to the same improvements in already healthy people). And, besides the hit to working memory, there are other recognised downsides to taking such drugs: common side effects of Adderall include headaches, digestive problems and insomnia. But this was a pilot study, and the sample size was certainly small. More work in the area is clearly needed.

—Neurocognitive, Autonomic, and Mood Effects of Adderall: A Pilot Study of Healthy College Students

Emma Young (@EmmaELYoung) is Staff Writer at BPS Research Digest