Recently I spoke on the phone with Barbara Sahakian, a clinical neuropsychologist at Cambridge University and the co-author of a 2007 article in Nature entitled "Professor's Little Helper". Sahakian, who also consults for several pharmaceutical companies, and her co-author, Sharon Morein-Zamir, reported that a number of their colleagues were using prescription drugs like Adderall and Provigil. Because the drugs are easy to buy online, they wrote, it would be difficult to stop their spread: "The drive for self-enhancement of cognition is likely to be as strong if not stronger than in the realms of 'enhancement' of beauty and sexual function." (In places like Cambridge, at least.)
Dr. Mosconi: I love apples. When I’m at the office though, I’ll bring homemade trail mix [made with] higher quality dried fruit, nuts and seeds. [It's] packed with brain-essential nutrients that come from goji berries, Brazil nuts, walnuts, cacao nibs, pistachios, hemp hearts and  more. Plus, I drink plenty of rose water throughout the day, which is very anti-inflammatory.
On the other hand, Phillips said, Provigil's effects "have attenuated over time. The body is an amazing adjusting machine, and there's no upside that I've been able to see to just taking more." A few years ago Phillips tired of poker and started playing competitive Scrabble. He was good, but not that good. He was older than many of his rivals and he needed to undertake a lot of rote memorisation, which didn't come as easily as it once had. "I stopped short of memorising the entire dictionary, and to be really good you have to get up to eight- and nine-letter words," he told me. "But I did learn every word up to five letters, plus maybe 10,000 seven- and eight-letter words." Provigil, he said, helped with the memorisation process but, "it's not going to make you smarter. It's going to make you better able to use the tools you have for a sustained period."
The use of prescription stimulants is especially prevalent among students.[9] Surveys suggest that 0.7–4.5% of German students have used cognitive enhancers in their lifetime.[10][11][12] Stimulants such as dimethylamylamine and methylphenidate are used on college campuses and by younger groups.[13] Based upon studies of self-reported illicit stimulant use, 5–35% of college students use diverted ADHD stimulants, which are primarily intended for performance enhancement rather than as recreational drugs.[14][15][16] Several factors positively and negatively influence an individual's willingness to use a drug for the purpose of enhancing cognitive performance. Among them are personal characteristics, drug characteristics, and characteristics of the social context.[10][11][17][18]