To judge from recent reports in the popular media, healthy people have also begun to use MPH and AMPs for cognitive enhancement. Major daily newspapers such as The New York Times, The LA Times, and The Wall Street Journal; magazines including Time, The Economist, The New Yorker, and Vogue; and broadcast news organizations including the BBC, CNN, and NPR have reported a trend toward growing use of prescription stimulants by healthy people for the purpose of enhancing school or work performance.
As already mentioned, AMPs and MPH are classified by the U.S. Food and Drug Administration (FDA) as Schedule II substances, which means that buying or selling them is a felony offense. This raises the question of how the drugs are obtained by students for nonmedical use. Several studies addressed this question and yielded reasonably consistent answers.

My first time was relatively short: 10 minutes around the F3/F4 points, with another 5 minutes to the forehead. Awkward holding it up against one’s head, and I see why people talk of LED helmets, it’s boring waiting. No initial impressions except maybe feeling a bit mentally cloudy, but that goes away within 20 minutes of finishing when I took a nap outside in the sunlight. Lostfalco says Expectations: You will be tired after the first time for 2 to 24 hours. It’s perfectly normal., but I’m not sure - my dog woke me up very early and disturbed my sleep, so maybe that’s why I felt suddenly tired. On the second day, I escalated to 30 minutes on the forehead, and tried an hour on my finger joints. No particular observations except less tiredness than before and perhaps less joint ache. Third day: skipped forehead stimulation, exclusively knee & ankle. Fourth day: forehead at various spots for 30 minutes; tiredness 5/6/7/8th day (11/12/13/4): skipped. Ninth: forehead, 20 minutes. No noticeable effects.
11:30 AM. By 2:30 PM, my hunger is quite strong and I don’t feel especially focused - it’s difficult to get through the tab-explosion of the morning, although one particularly stupid poster on the DNB ML makes me feel irritated like I might on Adderall. I initially figure the probability at perhaps 60% for Adderall, but when I wake up at 2 AM and am completely unable to get back to sleep, eventually racking up a Zeo score of 73 (compared to the usual 100s), there’s no doubt in my mind (95%) that the pill was Adderall. And it was the last Adderall pill indeed.
Nootropics are a great way to boost your productivity. Nootropics have been around for more than 40 years and today they are entering the mainstream. If you want to become the best you, nootropics are a way to level up your life. Nootropics are always personal and what works for others might not work for you. But no matter the individual outcomes, nootropics are here to make an impact!

Because executive functions tend to work in concert with one another, these three categories are somewhat overlapping. For example, tasks that require working memory also require a degree of cognitive control to prevent current stimuli from interfering with the contents of working memory, and tasks that require planning, fluency, and reasoning require working memory to hold the task goals in mind. The assignment of studies to sections was based on best fit, according to the aspects of executive function most heavily taxed by the task, rather than exclusive category membership. Within each section, studies are further grouped according to the type of task and specific type of learning, working memory, cognitive control, or other executive function being assessed.
A LessWronger found that it worked well for him as far as motivation and getting things done went, as did another LessWronger who sells it online (terming it a reasonable productivity enhancer) as did one of his customers, a pickup artist oddly enough. The former was curious whether it would work for me too and sent me Speciosa Pro’s Starter Pack: Test Drive (a sampler of 14 packets of powder and a cute little wooden spoon). In SE Asia, kratom’s apparently chewed, but the powders are brewed as a tea.
I largely ignored this since the discussions were of sub-RDA doses, and my experience has usually been that RDAs are a poor benchmark and frequently far too low (consider the RDA for vitamin D). This time, I checked the actual RDA - and was immediately shocked and sure I was looking at a bad reference: there was no way the RDA for potassium was seriously 3700-4700mg or 4-5 grams daily, was there? Just as an American, that implied that I was getting less than half my RDA. (How would I get 4g of potassium in the first place? Eat a dozen bananas a day⸮) I am not a vegetarian, nor is my diet that fantastic: I figured I was getting some potassium from the ~2 fresh tomatoes I was eating daily, but otherwise my diet was not rich in potassium sources. I have no blood tests demonstrating deficiency, but given the figures, I cannot see how I could not be deficient.
Smart Pill is a dietary supplement that blends vitamins, amino acids, and herbal extracts to sustain mental alertness, memory and concentration. One of the ingredients used in this formula is Vitamin B-1, also known as Thiamine, which sustains almost all functions present in the body, but plays a key role in brain health and function. A deficiency of this vitamin can lead to several neurological function problems. The most common use of Thiamine is to improve brain function; it acts as a neurotransmitter helping the brain prevent learning and memory disorders; it also provides help with mood disorders and offers stress relief.
Took pill 1:27 PM. At 2 my hunger gets the best of me (despite my usual tea drinking and caffeine+piracetam pills) and I eat a large lunch. This makes me suspicious it was placebo - on the previous days I had noted a considerable appetite-suppressant effect. 5:25 PM: I don’t feel unusually tired, but nothing special about my productivity. 8 PM; no longer so sure. Read and excerpted a fair bit of research I had been putting off since the morning. After putting away all the laundry at 10, still feeling active, I check. It was Adderall. I can’t claim this one either way. By 9 or 10 I had begun to wonder whether it was really Adderall, but I didn’t feel confident saying it was; my feeling could be fairly described as 50%.
To make things more interesting, I think I would like to try randomizing different dosages as well: 12mg, 24mg, and 36mg (1-3 pills); on 5 May 2014, because I wanted to finish up the experiment earlier, I decided to add 2 larger doses of 48 & 60mg (4-5 pills) as options. Then I can include the previous pilot study as 10mg doses, and regress over dose amount.

The Defense Department reports rely on data collected by the private real estate firms that operate base housing in partnership with military branches. The companies' compensation is partly determined by the results of resident satisfaction surveys. I had to re-read this sentence like 5 times to make sure I understood it correctly. I just can't even. Seriously, in what universe did anyone think that this would be a good idea?

With the right lifestyle and the right stack of supplements and nootropics, you can enjoy enhanced mental clarity, easier flow, and better vision. The best nootropics for your needs will depend on how much you want to spend, how often you want to take them, and what you want to take them for. Nutritional supplements should be taken daily, for the cumulative effect, but Smart drugs such as noopept and modafinil are usually taken on an as-needed basis, for those times when you are aiming for hyperfocus, better clarity, and better recall, or the ability to process a huge amount of incoming visual information quickly and accurately and to pick up on details that you might otherwise miss.


By which I mean that simple potassium is probably the most positively mind altering supplement I’ve ever tried…About 15 minutes after consumption, it manifests as a kind of pressure in the head or temples or eyes, a clearing up of brain fog, increased focus, and the kind of energy that is not jittery but the kind that makes you feel like exercising would be the reasonable and prudent thing to do. I have done no tests, but feel smarter from this in a way that seems much stronger than piracetam or any of the conventional weak nootropics. It is not just me – I have been introducing this around my inner social circle and I’m at 7/10 people felt immediately noticeable effects. The 3 that didn’t notice much were vegetarians and less likely to have been deficient. Now that I’m not deficient, it is of course not noticeable as mind altering, but still serves to be energizing, particularly for sustained mental energy as the night goes on…Potassium chloride initially, but since bought some potassium gluconate pills… research indicates you don’t want to consume large amounts of chloride (just moderate amounts).
Another prescription stimulant medication, modafinil (known by the brand name Provigil), is usually prescribed to patients suffering from narcolepsy and shift-work sleep disorder, but it might turn out to have broader applications. “We have conducted at the University of Cambridge double-blind, placebo-controlled studies in healthy people using modafinil and have found improvements in cognition, including in working memory,” Sahakian says. However, she doesn’t think everyone should start using the drug off-label. “There are no long-term safety and efficacy studies of modafinil in healthy people, and so it is unclear what the risks might be.”
2 commenters point out that my possible lack of result is due to my mistaken assumption that if nicotine is absorbable through skin, mouth, and lungs it ought to be perfectly fine to absorb it through my stomach by drinking it (rather than vaporizing it and breathing it with an e-cigarette machine) - it’s apparently known that absorption differs in the stomach.
Besides Adderall, I also purchased on Silk Road 5x250mg pills of armodafinil. The price was extremely reasonable, 1.5btc or roughly $23 at that day’s exchange rate; I attribute the low price to the seller being new and needing feedback, and offering a discount to induce buyers to take a risk on him. (Buyers bear a large risk on Silk Road since sellers can easily physically anonymize themselves from their shipment, but a buyer can be found just by following the package.) Because of the longer active-time, I resolved to test the armodafinil not during the day, but with an all-nighter.
1 PM; overall this was a pretty productive day, but I can’t say it was very productive. I would almost say even odds, but for some reason I feel a little more inclined towards modafinil. Say 55%. That night’s sleep was vile: the Zeo says it took me 40 minutes to fall asleep, I only slept 7:37 total, and I woke up 7 times. I’m comfortable taking this as evidence of modafinil (half-life 10 hours, 1 PM to midnight is only 1 full halving), bumping my prediction to 75%. I check, and sure enough - modafinil.
But how to blind myself? I used my pill maker to make 9 OO pills of piracetam mix, and then 9 OO pills of piracetam mix+the Adderall, then I put them in a baggy. The idea is that I can blind myself as to what pill I am taking that day since at the end of the day, I can just look in the baggy and see whether a placebo or Adderall pill is missing: the big capsules are transparent so I can see whether there is a crushed-up blue Adderall in the end or not. If there are fewer Adderall than placebo, I took an Adderall, and vice-versa. Now, since I am checking at the end of each day, I also need to remove or add the opposite pill to maintain the ratio and make it easy to check the next day; more importantly I need to replace or remove a pill, because otherwise the odds will be skewed and I will know how they are skewed. (Imagine I started with 4 Adderalls and 4 placebos, and then 3 days in a row I draw placebos but I don’t add or remove any pills; the next day, because most of the placebos have been used up, there’s only a small chance I will get a placebo…)
Smart pills are defined as drugs or prescription medication used to treat certain mental disorders, from milder ones such as brain fog, to some more severe like ADHD. They are often referred to as ‘nootropics’ but even though the two terms are often used interchangeably, smart pills and nootropics represent two different types of cognitive enhancers.
Most research on these nootropics suggest they have some benefits, sure, but as Barbara Sahakian and Sharon Morein-Zamir explain in the journal Nature, nobody knows their long-term effects. And we don’t know how extended use might change your brain chemistry in the long run. Researchers are getting closer to what makes these substances do what they do, but very little is certain right now. If you’re looking to live out your own Limitless fantasy, do your research first, and proceed with caution.
Going back to the 1960s, although it was a Romanian chemist who is credited with discovering nootropics, a substantial amount of research on racetams was conducted in the Soviet Union. This resulted in the birth of another category of substances entirely: adaptogens, which, in addition to benefiting cognitive function were thought to allow the body to better adapt to stress.
The data from 2-back and 3-back tasks are more complex. Three studies examined performance in these more challenging tasks and found no effect of d-AMP on average performance (Mattay et al., 2000, 2003; Mintzer & Griffiths, 2007). However, in at least two of the studies, the overall null result reflected a mixture of reliably enhancing and impairing effects. Mattay et al. (2000) examined the performance of subjects with better and worse working memory capacity separately and found that subjects whose performance on placebo was low performed better on d-AMP, whereas subjects whose performance on placebo was high were unaffected by d-AMP on the 2-back and impaired on the 3-back tasks. Mattay et al. (2003) replicated this general pattern of data with subjects divided according to genotype. The specific gene of interest codes for the production of Catechol-O-methyltransferase (COMT), an enzyme that breaks down dopamine and norepinephrine. A common polymorphism determines the activity of the enzyme, with a substitution of methionine for valine at Codon 158 resulting in a less active form of COMT. The met allele is thus associated with less breakdown of dopamine and hence higher levels of synaptic dopamine than the val allele. Mattay et al. (2003) found that subjects who were homozygous for the val allele were able to perform the n-back faster with d-AMP; those homozygous for met were not helped by the drug and became significantly less accurate in the 3-back condition with d-AMP. In the case of the third study finding no overall effect, analyses of individual differences were not reported (Mintzer & Griffiths, 2007).
The chemical Huperzine-A (Examine.com) is extracted from a moss. It is an acetylcholinesterase inhibitor (instead of forcing out more acetylcholine like the -racetams, it prevents acetylcholine from breaking down). My experience report: One for the null hypothesis files - Huperzine-A did nothing for me. Unlike piracetam or fish oil, after a full bottle (Source Naturals, 120 pills at 200μg each), I noticed no side-effects, no mental improvements of any kind, and no changes in DNB scores from straight Huperzine-A.

The miniaturization of electronic components has been crucial to smart pill design. As cloud computing and wireless communication platforms are integrated into the health care system, the use of smart pills for monitoring vital signs and medication compliance is likely to increase. In the long term, smart pills are expected to be an integral component of remote patient monitoring and telemedicine. As the call for noninvasive point-of-care testing increases, smart pills will become mainstream devices.
Christopher Wanjek is the Bad Medicine columnist for Live Science and a health and science writer based near Washington, D.C.  He is the author of two health books, "Food at Work" (2005) and "Bad Medicine" (2003), and a comical science novel, "Hey Einstein" (2012). For Live Science, Christopher covers public health, nutrition and biology, and he occasionally opines with a great deal of healthy skepticism. His "Food at Work" book and project, commissioned by the U.N.'s International Labor Organization, concerns workers health, safety and productivity. Christopher has presented this book in more than 20 countries and has inspired the passage of laws to support worker meal programs in numerous countries. Christopher holds a Master of Health degree from Harvard School of Public Health and a degree in journalism from Temple University. He has two Twitter handles, @wanjek (for science) and @lostlenowriter (for jokes).
As it happened, Health Supplement Wholesalers (since renamed Powder City) offered me a sample of their products, including their 5g Noopept powder ($13). I’d never used HSW before & they had some issues in the past; but I haven’t seen any recent complaints, so I was willing to try them. My 5g from batch #130830 arrived quickly (photos: packaging, powder contents). I tried some (tastes just slightly unpleasant, like an ultra-weak piracetam), and I set about capping the fluffy white flour-like powder with the hilariously tiny scoop they provide.
I tried taking whole pills at 1 and 3 AM. I felt kind of bushed at 9 AM after all the reading, and the 50 minute nap didn’t help much - I was sleep only around 10 minutes and spent most of it thinking or meditation. Just as well the 3D driver is still broken; I doubt the scores would be reasonable. Began to perk up again past 10 AM, then felt more bushed at 1 PM, and so on throughout the day; kind of gave up and began watching & finishing anime (Amagami and Voices of a Distant Star) for the rest of the day with occasional reading breaks (eg. to start James C. Scotts Seeing Like A State, which is as described so far). As expected from the low quality of the day, the recovery sleep was bigger than before: a full 10 hours rather than 9:40; the next day, I slept a normal 8:50, and the following day ~8:20 (woken up early); 10:20 (slept in); 8:44; 8:18 (▁▇▁▁). It will be interesting to see whether my excess sleep remains in the hour range for ’good modafinil nights and two hours for bad modafinil nights.
There is evidence to suggest that modafinil, methylphenidate, and amphetamine enhance cognitive processes such as learning and working memory...at least on certain laboratory tasks. One study found that modafinil improved cognitive task performance in sleep-deprived doctors. Even in non-sleep deprived healthy volunteers, modafinil improved planning and accuracy on certain cognitive tasks. Similarly, methylphenidate and amphetamine also enhanced performance of healthy subjects in certain cognitive tasks.
I have no particularly compelling story for why this might be a correlation and not causation. It could be placebo, but I wasn’t expecting that. It could be selection effect (days on which I bothered to use the annoying LED set are better days) but then I’d expect the off-days to be below-average and compared to the 2 years of trendline before, there doesn’t seem like much of a fall.
Swanson J, Arnold LE, Kraemer H, Hechtman L, Molina B, Hinshaw S, Wigal T. Evidence, interpretation and qualification from multiple reports of long-term outcomes in the Multimodal Treatment Study of Children With ADHD (MTA): Part II. Supporting details. Journal of Attention Disorders. 2008;12:15–43. doi: 10.1177/1087054708319525. [PubMed] [CrossRef]

Neuroplasticity, or the brain's ability to change and reorganize itself in response to intrinsic and extrinsic factors, indicates great potential for us to enhance brain function by medical or other interventions. Psychotherapy has been shown to induce structural changes in the brain. Other interventions that positively influence neuroplasticity include meditation, mindfulness , and compassion.


Table 1 shows all of the studies of middle school, secondary school, and college students that we identified. As indicated in the table, the studies are heterogeneous, with varying populations sampled, sample sizes, and year of data collection, and they focused on different subsets of the epidemiological questions addressed here, including prevalence and frequency of use, motivations for use, and method of obtaining the medication.
In the largest nationwide study, McCabe et al. (2005) sampled 10,904 students at 119 public and private colleges and universities across the United States, providing the best estimate of prevalence among American college students in 2001, when the data were collected. This survey found 6.9% lifetime, 4.1% past-year, and 2.1% past-month nonmedical use of a prescription stimulant. It also found that prevalence depended strongly on student and school characteristics, consistent with the variability noted among the results of single-school studies. The strongest predictors of past-year nonmedical stimulant use by college students were admissions criteria (competitive and most competitive more likely than less competitive), fraternity/sorority membership (members more likely than nonmembers), and gender (males more likely than females).

One claim was partially verified in passing by Eliezer Yudkowsky (Supplementing potassium (citrate) hasn’t helped me much, but works dramatically for Anna, Kevin, and Vassar…About the same as drinking a cup of coffee - i.e., it works as a perker-upper, somehow. I’m not sure, since it doesn’t do anything for me except possibly mitigate foot cramps.)
Caveats aside, if you do want to try a nootropic, consider starting with something simple and pretty much risk-free, like aromatherapy with lemon essential oil or frankincense, which can help activate your brain, Barbour says. You could also sip on "golden milk," a sweet and anti-inflammatory beverage made with turmeric, or rosemary-infused water, she adds.
There are a number of treatments for the last. I already use melatonin. I sort of have light therapy from a full-spectrum fluorescent desk lamp. But I get very little sunlight; the surprising thing would be if I didn’t have a vitamin D deficiency. And vitamin D deficiencies have been linked with all sorts of interesting things like near-sightedness, with time outdoors inversely correlating with myopia and not reading or near-work time. (It has been claimed that caffeine interferes with vitamin D absorption and so people like me especially need to take vitamin D, on top of the deficits caused by our vampiric habits, but I don’t think this is true34.) Unfortunately, there’s not very good evidence that vitamin D supplementation helps with mood/SAD/depression: there’s ~6 small RCTs with some findings of benefits, with their respective meta-analysis turning in a positive but currently non-statistically-significant result. Better confirmed is reducing all-cause mortality in elderly people (see, in order of increasing comprehensiveness: Evidence Syntheses 2013, Chung et al 2009, Autier & Gandini 2007, Bolland et al 2014).
Yet some researchers point out these drugs may not be enhancing cognition directly, but simply improving the user’s state of mind – making work more pleasurable and enhancing focus. “I’m just not seeing the evidence that indicates these are clear cognition enhancers,” says Martin Sarter, a professor at the University of Michigan, who thinks they may be achieving their effects by relieving tiredness and boredom. “What most of these are actually doing is enabling the person who’s taking them to focus,” says Steven Rose, emeritus professor of life sciences at the Open University. “It’s peripheral to the learning process itself.”

One of the most widely known classes of smart drugs on the market, Racetams, have a long history of use and a lot of evidence of their effectiveness. They hasten the chemical exchange between brain cells, directly benefiting our mental clarity and learning process. They are generally not controlled substances and can be purchased without a prescription in a lot of locations globally.


The concept of neuroenhancement and the use of substances to improve cognitive functioning in healthy individuals, is certainly not a new one. In fact, one of the first cognitive enhancement drugs, Piracetam, was developed over fifty years ago by psychologist and chemist C.C. Giurgea. Although he did not know the exact mechanism, Giurgia believed the drug boosted brain power and so began his exploration into "smart pills", or nootropics, a term he coined from the Greek nous, meaning "mind," and trepein, meaning "to bend.  
…Four subjects correctly stated when they received nicotine, five subjects were unsure, and the remaining two stated incorrectly which treatment they received on each occasion of testing. These numbers are sufficiently close to chance expectation that even the four subjects whose statements corresponded to the treatments received may have been guessing.
Bought 5,000 IU soft-gels of Vitamin D-333 (Examine.com; FDA adverse events) because I was feeling very apathetic in January 2011 and not getting much done, even slacking on regular habits like Mnemosyne spaced repetition review or dual n-back or my Wikipedia watchlist. Introspecting, I was reminded of depression & dysthymia & seasonal affective disorder.
Nootroo and Nootrobox are two San Francisco nootropics startups that launched last year. Their founders come from the tech scene and their products are squarely aimed at the tech crowd seeking the convenience of not having to build their own combinations. Each claims big-name Silicon Valley entrepreneurs and investors among their users, though neither will name them.
See Melatonin for information on effects & cost; I regularly use melatonin to sleep (more to induce sleep than prolong or deepen it), and investigating with my Zeo, it does seem to improve & shorten my sleep. Some research suggests that higher doses are not necessarily better and may be overkill, so each time I’ve run out, I’ve been steadily decreasing the dose from 3mg to 1.5mg to 1mg, without apparently compromising the usefulness.
…researchers have added a new layer to the smart pill conversation. Adderall, they’ve found, makes you think you’re doing better than you actually are….Those subjects who had been given Adderall were significantly more likely to report that the pill had caused them to do a better job….But the results of the new University of Pennsylvania study, funded by the U.S. Navy and not yet published but presented at the annual Society for Neuroscience conference last month, are consistent with much of the existing research. As a group, no overall statistically-significant improvement or impairment was seen as a result of taking Adderall. The research team tested 47 subjects, all in their 20s, all without a diagnosis of ADHD, on a variety of cognitive functions, from working memory-how much information they could keep in mind and manipulate-to raw intelligence, to memories for specific events and faces….The last question they asked their subjects was: How and how much did the pill influence your performance on today’s tests? Those subjects who had been given Adderall were significantly more likely to report that the pill had caused them to do a better job on the tasks they’d been given, even though their performance did not show an improvement over that of those who had taken the placebo. According to Irena Ilieva…it’s the first time since the 1960s that a study on the effects of amphetamine, a close cousin of Adderall, has asked how subjects perceive the effect of the drug on their performance.
The price is not as good as multivitamins or melatonin. The studies showing effects generally use pretty high dosages, 1-4g daily. I took 4 capsules a day for roughly 4g of omega acids. The jar of 400 is 100 days’ worth, and costs ~$17, or around 17¢ a day. The general health benefits push me over the edge of favoring its indefinite use, but looking to economize. Usually, small amounts of packaged substances are more expensive than bulk unprocessed, so I looked at fish oil fluid products; and unsurprisingly, liquid is more cost-effective than pills (but like with the powders, straight fish oil isn’t very appetizing) in lieu of membership somewhere or some other price-break. I bought 4 bottles (16 fluid ounces each) for $53.31 total (thanks to coupons & sales), and each bottle lasts around a month and a half for perhaps half a year, or ~$100 for a year’s supply. (As it turned out, the 4 bottles lasted from 4 December 2010 to 17 June 2011, or 195 days.) My next batch lasted 19 August 2011-20 February 2012, and cost $58.27. Since I needed to buy empty 00 capsules (for my lithium experiment) and a book (Stanovich 2010, for SIAI work) from Amazon, I bought 4 more bottles of 16fl oz Nature’s Answer (lemon-lime) at $48.44, which I began using 27 February 2012. So call it ~$70 a year.
Fish oil (Examine.com, buyer’s guide) provides benefits relating to general mood (eg. inflammation & anxiety; see later on anxiety) and anti-schizophrenia; it is one of the better supplements one can take. (The known risks are a higher rate of prostate cancer and internal bleeding, but are outweighed by the cardiac benefits - assuming those benefits exist, anyway, which may not be true.) The benefits of omega acids are well-researched.

as scientific papers become much more accessible online due to Open Access, digitization by publishers, and cheap hosting for pirates, the available knowledge about nootropics increases drastically. This reduces the perceived risk by users, and enables them to educate themselves and make much more sophisticated estimates of risk and side-effects and benefits. (Take my modafinil page: in 1997, how could an average person get their hands on any of the papers available up to that point? Or get detailed info like the FDA’s prescribing guide? Even assuming they had a computer & Internet?)
The one indisputable finding from the literature so far is that many people are seeking cognitive enhancement. Beyond that, the literature yields only partial and tentative answers to the questions just raised. Given the potential impact of cognitive enhancement on society, more research is needed. For research on the epidemiology of cognitive enhancement, studies focused on the cognitive-enhancement practices and experiences of students and nonstudent workers are needed. For research on the cognitive effects of prescription stimulants, larger samples are needed. Only with substantially larger samples will it be possible to assess small but potentially important benefits, as well as risks, and to distinguish individual differences in drug response. Large samples would also be required to compare these effects to the cognitive effects of improved sleep, exercise, nutrition, and stress management. To include more ecologically valid measures of cognition in academic and work environments would in addition require the equivalent of a large clinical trial.

Flow diagram of cognitive neuroscience literature search completed July 2, 2010. Search terms were dextroamphetamine, Aderrall, methylphenidate, or Ritalin, and cognitive, cognition, learning, memory, or executive function, and healthy or normal. Stages of subsequent review used the information contained in the titles, abstracts, and articles to determine whether articles reported studies meeting the inclusion criteria stated in the text.
l-Theanine – A 2014 systematic review and meta-analysis found that concurrent caffeine and l-theanine use had synergistic psychoactive effects that promoted alertness, attention, and task switching;[29] these effects were most pronounced during the first hour post-dose.[29] However, the European Food Safety Authority reported that, when L-theanine is used by itself (i.e. without caffeine), there is insufficient information to determine if these effects exist.[34]
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