Cognitive Enhancement is often defined as the effort to increase the performance of cognitive function like attention and concentration, memory, problem-solving in healthy individuals. While every species including humans have consistently and continuously evolved day by day to improve themselves. However, using medications and technological advances in increasing cognitive functions is a relatively new aspect and is a matter of debate on the ground of ethical, philosophical and sociopolitical.
Here it's very important to understand that use of medications is off-label and there is a little evidence of efficacy.
Psychostimulants include Methylphenidate and dextroamphetamine. These are commonly used to treat ADHD, Narcolepsy, fatigue associated with cancer, and in depression as an augmentation strategy. However, they have side effects like decreased appetite and weight, insomnia, headache, irritability, and mood changes, palpitations, tachycardia, and potential of abuse. Analysis of current literature suggests no or little evidence except slight positive effect on memory. So, use of psychostimulant to enhance cognitive function should be used cautiously keeping in mind the potential side effects caused by them.
Modafinil a wake-promoting agent that has been mainly used by the healthy individual like students, academics and physician. It is also used to treat ADHD and narcolepsy however it has life-threatening side effects in children, that's why FDA did not approve it for ADHD. Reseach has shown a moderate effect of Modafinil on attention in well-rested individual and more pronounced in sleep-deprived individuals which might be due to "overconfidence" effect.
Other medications like Cholinesterase inhibitors and the NMDA antagonist memantine have shows no consistent effect even they are well tolerated.
Individuals suffering from ADHD or Narcolepsy are compelled to take the stimulant to maintain pace with their peers. However, use in the healthy individual has complicated issues. As cognitive enhancer increased productivity in some profession in which sustained concentration is required, the risk of abuse or potential side effects like weight losses, the cardiac risk may outweigh the potential benefits. Finally, they predispose the individuals to the risk of substance use.