Sleep is not as sacred as it once was. A decent eight hours of sleep used to be a prerequisite before and after a long day of hard work. On the contrary, modern society approaches work more in an “if you don’t lose sleep over it, you are not working hard enough” kind of way. And this while skimping on sleep wreaks havoc from head to toe: especially your head.

It is well established that sleep deprivation has damaging consequences, grumpiness being the least of your problems. For one, lack of sleep impairs the function of neurotransmitter receptors in brain areas involved in learning and memory, such as the hippocampus. Put simply, cutting on sleep gives neurotransmitters, chemical messengers driving a wide area of cognitive functions, a hard time doing their job. This damaging impact mainly concerns attention and working memory. For example, have you started reading this piece for the third time because the words didn’t make sense the first or second? That may be a case of bad writing, but it may very well be your sleeping habits. In short, lack of sleep takes away optimal cognitive functioning, while leaving you with an overall feeling of drowsiness.

So what if you need those cognitive functions and want away with the drowsiness?

In come the “eugregorics”. Although that may not sound like something you would want to encounter late at night, if you want to stay awake you may want to reconsider. Eugregorics is the overarching name for a new group of drugs that mimic the stimulating effects of amphetamines. They stimulate wakefulness, but do so without the typical negative side effects that come with amphetamines. Modafinil is one such drug. It is used, amongst others, against narcolepsy, a chronic neurologic disorder characterized by excessive daytime sleepiness. But can modafinil counteract the effects of sleep deprivation in healthy sleep deprived people as well?

Several studies have found that the drug can enhance performance during periods of sleep deficiency in healthy people. For example, Stivalet and colleagues (1998) found that it maintained attention processing throughout 60 hours of sleep deprivation. As a matter of fact, military personnel already use modafinil to ensure performance in missions of great duration.

However, Repantis and colleagues (2006) concluded that successful cognitive enhancement may only account for a single dose of modafinil after a moderate period of sleep deprivation. In repeated doses over a longer period of time, the drug only seems to maintain wakefulness. Sleep deprived individuals who took modafinil also appeared to be victim of an overconfidence effect: they overrated their own cognitive performance.

In sum, modafinil can enhance cognitive performance when sleep deprived, but this effect seems to diminish over time. Adding this to the overconfidence effect, modafinil may not be a long-term solution for enhancing cognition. Although military personnel may use it in desperate measures, we may want to consider tucking in a bit earlier. But, if you’re in combat with your work and in dire need of some one-time back-up: modafinil may be your man.