SOURCES: Ray Sahelian, MD. Psychopharmacology, September 2000. Human Psychopharmacology, July 2001; January 2002. Psychopharmacology Bulletin, Summer 2002. The Cochrane Database of Systematic Reviews, 2002. Archives of Neurology, November 1998. Zhongguo Yao Li Xue Bao, July 1999. Pharmacological Research, September 1999. International Clinical Psychopharmacology, March 2003. FDA web site.
For the moment, people looking for that particular quick fix have a limited choice of meds. But given the amount of money and research hours being spent on developing drugs to treat cognitive decline, Provigil and Adderall are likely to be joined by a bigger pharmacopoeia. Among the drugs in the pipeline are ampakines, which target a type of glutamate receptor in the brain; it is hoped that they may stem the memory loss associated with diseases like Alzheimer's. But ampakines may also give healthy people a palpable cognitive boost. A 2007 study of 16 healthy elderly volunteers found that 500mg of one particular ampakine "unequivocally" improved short-term memory, though it appeared to detract from episodic memory - the recall of past events. Another class of drugs, cholinesterase inhibitors, which are already being used with some success to treat Alzheimer's patients, have also shown promise as neuroenhancers. In one study the drug donepezil strengthened the performance of pilots on flight simulators; in another, of 30 healthy young male volunteers, it improved verbal and visual episodic memory. Several pharmaceutical companies are working on drugs that target nicotine receptors in the brain in the hope that they can replicate the cognitive uptick that smokers get from cigarettes.
Finally, it’s not clear that caffeine results in performance gains after long-term use; homeostasis/tolerance is a concern for all stimulants, but especially for caffeine. It is plausible that all caffeine consumption does for the long-term chronic user is restore performance to baseline. (Imagine someone waking up and drinking coffee, and their performance improves - well, so would the performance of a non-addict who is also slowly waking up!) See for example, James & Rogers 2005, Sigmon et al 2009, and Rogers et al 2010. A cross-section of thousands of participants in the Cambridge brain-training study found caffeine intake showed negligible effect sizes for mean and component scores (participants were not told to use caffeine, but the training was recreational & difficult, so one expects some difference).
Nootropics (/noʊ.əˈtrɒpɪks/ noh-ə-TROP-iks) (colloquial: smart drugs and cognitive enhancers) are drugs, supplements, and other substances that may improve cognitive function, particularly executive functions, memory, creativity, or motivation, in healthy individuals. While many substances are purported to improve cognition, research is at a preliminary stage as of 2018, and the effects of the majority of these agents are not fully determined.