Adderall and IQ: Does Adderall Make You Smarter? | Riot IQ
Oct 14, 2026·Advanced Topics & Research
Adderall and IQ: Does Adderall Make You Smarter?
Adderall and IQ: stimulants do not raise intelligence in healthy people. Lab gains are small, about 0 to 3 IQ-point equivalents, and mostly reflect motivation.
Dr. Russell T. WarneChief Scientist
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Adderall does not raise IQ in healthy people: in a carefully controlled trial it produced no reliable gain on 13 cognitive measures, including Raven's matrices, and meta-analyses of stimulants in healthy adults find small effects, roughly 0 to 3 IQ-point equivalents depending on the drug. What users notice most is more energy and motivation, which feels like being smarter and does not show up as better reasoning.
This page covers what the controlled studies show in healthy adults, why the "smart pill" reputation persists, what stimulant medication does and does not do for people with ADHD, and the risks that come with the drug. It describes research findings and is not medical advice.
What Adderall is and why people call it a smart pill
Adderall is a prescription mix of amphetamine salts. Its approved uses in the United States are ADHD and narcolepsy, and it is a Schedule II controlled substance, the strictest category for drugs with an accepted medical use. Methylphenidate (Ritalin and similar brands) works in a similar way and is usually studied alongside it.
The "smart pill" idea comes mostly from students. In a national survey of 10,904 students at 119 four-year US colleges, 6.9% reported using a prescription stimulant without a prescription at some point and 4.1% in the past year. Past-year use ranged from zero to 25% depending on the college, and it was higher at colleges with more competitive admissions. One detail rarely makes it into the "study drug" story: non-medical users had lower grade point averages than non-users. That fits students reaching for a fix when they fall behind more than it fits a drug that turns people into high achievers.
What the controlled studies show in healthy people
The best evidence comes from double-blind trials where neither the participant nor the researcher knows whether a given dose is the drug or a placebo. A major 2011 review by Elizabeth Smith and Martha Farah concluded that stimulants can improve some kinds of memory in healthy people, while effects on working memory and self-control are less reliable.
• The Adderall trial with IQ-type tests: Irena Ilieva, Joseph Boland and Martha Farah gave healthy young adults Adderall and a placebo on separate days and measured 13 abilities, including memory, inhibitory control, creativity, Raven's Progressive Matrices (a classic nonverbal reasoning test that loads heavily on general intelligence) and scholastic achievement. Adderall did not enhance any of these abilities for participants in general. There were hints that lower-scoring participants gained on a few tasks, including Raven's, but the authors concluded that the drug has "no more than small effects" on cognition in healthy young adults.
• The 2015 meta-analysis: pooling 48 studies with 1,409 healthy participants, Ilieva, Hook and Farah found small improvements in inhibitory control and short-term memory, a small and less certain effect on working memory, and a medium effect on memory tested after a delay. Signs of publication bias (positive studies being more likely to be published) led them to call the overall effect "probably modest."
• The 2020 meta-analyses: Carl Roberts and colleagues analysed 47 studies of single doses in healthy, rested adults. Methylphenidate had a small overall effect (a standardised mean difference of 0.21), mostly from recall and sustained attention. Dextroamphetamine, the main ingredient of Adderall, had no significant effect at all. Modafinil, a wakefulness drug sometimes lumped in with stimulants, had a very small effect of 0.12.
To put those numbers on the IQ scale: a standardised effect expresses a difference in "standard deviation" units (the typical spread of scores around the average), and the IQ standard deviation is 15 points. An effect of 0.21 would be about 3 IQ-point equivalents and 0.12 about 2. Those are effects on memory and attention tasks, not on full IQ tests, so the conversion is an upper bound on what the drug does to reasoning. For comparison, our page on caffeine and IQ describes a similar pattern: a temporary lift in alertness that shows up on speed and attention tasks more than on reasoning.
Stimulants can even make hard thinking worse. In a 2023 study, Elizabeth Bowman and colleagues gave 40 healthy adults methylphenidate, dextroamphetamine, modafinil and a placebo in separate sessions, then had them solve "knapsack" problems, a puzzle that mirrors everyday planning. On the drugs, people worked longer and took more steps, yet the quality of their solutions fell. Above-average performers often slipped below average. The authors' summary is that the drugs raise motivation while lowering the quality of effort.
Why people believe it works
If the measured effects are this small, why are users so convinced? The answer seems to lie in motivation and perception.
In the Ilieva trial, participants believed their performance was better on the drug than on placebo, even though the tests did not show it. In a separate survey of people who used stimulants for studying, Ilieva and Farah found that users rated the boost to "energy" and "motivation" at least as highly as the boost to attention. Studying a dull subject for six hours is easier when the work feels more interesting, and that can feel like being sharper.
Grades tell the same story. Amelia Arria and colleagues followed 898 undergraduates without ADHD over two years and compared grade point averages from college records. Students who never used stimulants without a prescription improved their GPA over the period. Students who started, stopped or kept using did not improve, and none of the user groups gained any detectable advantage over their peers.
A third reason is an old misunderstanding. People used to think that stimulants calm children with ADHD "paradoxically," and that a good response therefore proved the diagnosis. A 1978 study by Judith Rapoport and colleagues gave a single dose of dextroamphetamine to 14 boys without ADHD. They became less active, reacted faster and did better on cognitive tests, much as children with ADHD do. Stimulants act on everyone's attention in similar ways, which is why a good day on Adderall says little about anyone's underlying ability.
What stimulants do for people with ADHD
For people diagnosed with ADHD the picture is different, because the drug is treating symptoms that get in the way of showing what they know. How ADHD itself relates to measured intelligence is covered in our article on ADHD and IQ, and medication does not change the underlying ability.
A Swedish register study by Yi Lu and colleagues compared 930 people with ADHD who took the national university entrance test more than once, sometimes while on medication and sometimes not. Comparing each person with themselves, scores were 4.80 points higher (on a scale of up to 200) during medicated periods, after adjusting for age and practice. The within-person design rules out stable differences between people, though not everything that changes over time.
Learning is another matter. In a randomised crossover trial, William Pelham and colleagues taught 173 children with ADHD, aged 7 to 12, science, social studies and vocabulary in a summer classroom, with each child on methylphenidate for one three-week unit and a placebo for the other. On medication, children completed far more seatwork and behaved better every day. They did not learn more: the amount of material learned was the same on drug and placebo.
So the evidence is consistent across groups. Stimulants help people with ADHD perform closer to their ability on the day, and they make seatwork easier, but there is no sign they raise intelligence in anyone.
Risks and who to talk to
The US prescribing information for Adderall carries a boxed warning, the FDA's most serious label warning. It states that Adderall has "a high potential for abuse and misuse, which can lead to the development of a substance use disorder, including addiction," and that misuse can result in overdose and death, especially at higher doses or when the drug is snorted or injected. The label also lists effects of misuse such as a racing heart, raised blood pressure, insomnia, loss of appetite and anxiety, and warns of serious risks for people with heart disease.
Taking someone else's prescription removes the safeguards that come with a prescriber's assessment. Anyone who thinks they may have ADHD, or who is struggling to concentrate, should talk to a GP, a psychiatrist or another licensed prescriber, who can assess the cause and discuss options. Questions about an existing prescription belong with the prescriber or a pharmacist.
Frequently asked questions
Does Adderall increase your IQ?
No. In healthy adults, a controlled trial found no reliable gain on 13 measures including Raven's matrices, and meta-analyses find small effects on memory and attention, with no significant effect for dextroamphetamine.
Why do people feel smarter on Adderall?
Mainly because of increased energy, motivation and confidence. In a placebo-controlled trial, users believed they performed better on the drug even when the tests showed no improvement.
Does Adderall help students get better grades?
A two-year study of 898 undergraduates found that students who used stimulants without a prescription gained no detectable GPA advantage over their peers, while non-users' grades improved.
Does ADHD medication improve test scores?
It can help people with ADHD perform better on the day: in a Swedish study, entrance-test scores were 4.80 points higher (on a scale of up to 200) during medicated periods. A classroom trial found children did more work on medication but did not learn more.
Is modafinil a better smart drug?
The evidence is no stronger. A 2020 meta-analysis found a very small overall effect of modafinil in healthy, rested adults, and a 2023 study found it lowered the quality of solutions on complex problems.
The takeaway
Adderall changes how alert and driven people feel, and in people with ADHD it can help them show what they know. It does not make anyone more intelligent. The best trials in healthy people find small or zero effects on memory and attention and nothing reliable on reasoning tests, while the risk of misuse is serious enough to earn the FDA's strongest warning. Your reasoning ability is far better measured than medicated, and if you want an accurate picture of yours, take a professionally developed IQ test.
References
1. McCabe, S. E., Knight, J. R., Teter, C. J., & Wechsler, H. (2005). Non-medical use of prescription stimulants among US college students: Prevalence and correlates from a national survey. Addiction, 100(1), 96-106. [doi.org/10.1111/j.1360-0443.2005.00944.x](. doi.org
2. Ilieva, I., Boland, J., & Farah, M. J. (2013). Objective and subjective cognitive enhancing effects of mixed amphetamine salts in healthy people. Neuropharmacology, 64, 496-505. [doi.org/10.1016/j.neuropharm.2012.07.021](. doi.org
3. Ilieva, I. P., Hook, C. J., & Farah, M. J. (2015). Prescription stimulants' effects on healthy inhibitory control, working memory, and episodic memory: A meta-analysis. Journal of Cognitive Neuroscience, 27(6), 1069-1089. [doi.org/10.1162/jocn_a_00776](. doi.org
4. Roberts, C. A., Jones, A., Sumnall, H., Gage, S. H., & Montgomery, C. (2020). How effective are pharmaceuticals for cognitive enhancement in healthy adults? A series of meta-analyses of cognitive performance during acute administration of modafinil, methylphenidate and D-amphetamine. European Neuropsychopharmacology, 38, 40-62. [doi.org/10.1016/j.euroneuro.2020.07.002](. doi.org
5. Bowman, E., Coghill, D., Murawski, C., & Bossaerts, P. (2023). Not so smart? "Smart" drugs increase the level but decrease the quality of cognitive effort. Science Advances, 9(24), eadd4165. [doi.org/10.1126/sciadv.add4165](. doi.org
6. Ilieva, I. P., & Farah, M. J. (2013). Enhancement stimulants: Perceived motivational and cognitive advantages. Frontiers in Neuroscience, 7, 198. [doi.org/10.3389/fnins.2013.00198](. doi.org
7. Arria, A. M., Caldeira, K. M., Vincent, K. B., O'Grady, K. E., Cimini, M. D., Geisner, I. M., Fossos-Wong, N., Kilmer, J. R., & Larimer, M. E. (2017). Do college students improve their grades by using prescription stimulants nonmedically? Addictive Behaviors, 65, 245-249. [doi.org/10.1016/j.addbeh.2016.07.016](. doi.org
8. Rapoport, J. L., Buchsbaum, M. S., Zahn, T. P., Weingartner, H., Ludlow, C., & Mikkelsen, E. J. (1978). Dextroamphetamine: Cognitive and behavioral effects in normal prepubertal boys. Science, 199(4328), 560-563. [doi.org/10.1126/science.341313](. doi.org
9. Lu, Y., Sjölander, A., Cederlöf, M., D'Onofrio, B. M., Almqvist, C., Larsson, H., & Lichtenstein, P. (2017). Association between medication use and performance on higher education entrance tests in individuals with attention-deficit/hyperactivity disorder. JAMA Psychiatry, 74(8), 815-822. [doi.org/10.1001/jamapsychiatry.2017.1472](. doi.org
10. Pelham, W. E., Altszuler, A. R., Merrill, B. M., Raiker, J. S., Macphee, F. L., Ramos, M., Gnagy, E. M., Greiner, A. R., Coles, E. K., Connor, C. M., Lonigan, C. J., Burger, L., Morrow, A. S., Zhao, X., Swanson, J. M., Waxmonsky, J. G., & Pelham, W. E. (2022). The effect of stimulant medication on the learning of academic curricula in children with ADHD: A randomized crossover study. Journal of Consulting and Clinical Psychology, 90(5), 367-380. [doi.org/10.1037/ccp0000725](. doi.org
11. Smith, M. E., & Farah, M. J. (2011). Are prescription stimulants "smart pills"? The epidemiology and cognitive neuroscience of prescription stimulant use by normal healthy individuals. Psychological Bulletin, 137(5), 717-741. [doi.org/10.1037/a0023825](. doi.org
12. Teva Pharmaceuticals USA. (2024). Adderall (dextroamphetamine saccharate, amphetamine aspartate, dextroamphetamine sulfate and amphetamine sulfate tablets): Prescribing information. DailyMed, US National Library of Medicine. [dailymed.nlm.nih.gov](. dailymed.nlm.nih.gov
Hero image: Daily pills, by ProjectManhattan, CC BY-SA 3.0. Via Wikimedia Commons.
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