Lost confidence.  If you can’t find your keys, much less get through your workday in a timely fashion without a slew of mistakes, you are going to lose confidence in both your brain and yourself.  When you cannot remember where you put things and it takes an absurd amount of effort just to do a simple task, you might question your very sanity.  As your confidence continues to nose-dive, you just end up making more and more mistakes.  It turns into a vicious cycle.
The main concern with pharmaceutical drugs is adverse effects, which also apply to nootropics with undefined effects. Long-term safety evidence is typically unavailable for nootropics.[13] Racetams — piracetam and other compounds that are structurally related to piracetam — have few serious adverse effects and low toxicity, but there is little evidence that they enhance cognition in people having no cognitive impairments.[19]
People charged with doing simple tasks did not exhibit much of an increase in brain function after taking Modafinil, but their performance on complex and difficult tasks after taking the drug was significantly better than those who were given a placebo. This suggests that it may affect “higher cognitive functions—mainly executive functions but also attention and learning,” explains study co-author Ruairidh Battleday.

Dr Hart talked through food intolerance tests that are available through a number of well known companies, including York Test for whom she is Scientific Director. A possible strategy could be to use such testing to identify intolerances, follow an elimination protocol, temporarily removing on foods triggering an IgG response; and then work to improve your gut health to support longer term well-being. Foods that are rich in collagen and its amino acids, like glycine and proline, are great for healing connective tissue, which is what the intestines are made up of. A traditional food, rich in these amino acids, that has made its way into our kitchens again after rediscovering its therapeutic properties is bone broth. Another example of a group of traditional foods that can be used therapeutically in building digestive health, are fermented foods such as kefir, sauerkraut and kimchi. These are abundant in probiotics, which are the ‘good’ bacteria our digestive system needs to help keep a good balance and protect the intestinal barrier from pathogens, toxins and parasites. Once these foods have been introduced on an everyday basis along with eating a healthy nutrient-dense diet and the possible use of supplements to help restore balance, you may be able to reintroduce foods that were previously triggering an IgG response carefully, one at a time, whilst monitoring symptoms.
I almost resigned myself to buying patches to cut (and let the nicotine evaporate) and hope they would still stick on well enough afterwards to be indistinguishable from a fresh patch, when late one sleepless night I realized that a piece of nicotine gum hanging around on my desktop for a week proved useless when I tried it, and that was the answer: if nicotine evaporates from patches, then it must evaporate from gum as well, and if gum does evaporate, then to make a perfect placebo all I had to do was cut some gum into proper sizes and let the pieces sit out for a while. (A while later, I lost a piece of gum overnight and consumed the full 4mg to no subjective effect.) Google searches led to nothing indicating I might be fooling myself, and suggested that evaporation started within minutes in patches and a patch was useless within a day. Just a day is pushing it (who knows how much is left in a useless patch?), so I decided to build in a very large safety factor and let the gum sit for around a month rather than a single day.
10:30 AM; no major effect that I notice throughout the day - it’s neither good nor bad. This smells like placebo (and part of my mind is going how unlikely is it to get placebo 3 times in a row!, which is just the Gambler’s fallacy talking inasmuch as this is sampling with replacement). I give it 60% placebo; I check the next day right before taking, and it is. Man!
Systematic reviews and meta-analyses of clinical human research using low doses of certain central nervous system stimulants found enhanced cognition in healthy people.[21][22][23] In particular, the classes of stimulants that demonstrate cognition-enhancing effects in humans act as direct agonists or indirect agonists of dopamine receptor D1, adrenoceptor A2, or both types of receptor in the prefrontal cortex.[21][22][24][25] Relatively high doses of stimulants cause cognitive deficits.[24][25]