Cognitive Enhancement: A Crutch to Cope with Less Sleep?


by Brenda Patoine

July, 2008

The rising use of various medications to boost cognitive performance and the prospect of more “memory drugs” on the horizon raise a slew of ethical questions. But an even more fundamental question is whether such drugs are being used as a substitute for sleep—itself a cognitive enhancer of sorts.

Americans are widely regarded as chronically sleep-deprived; the American Psychological Association says very few adults regularly obtain the eight or more hours of sleep needed nightly. Accordingly, concern is growing that some people are using medications such as modafinil (Provigil), methylphenidate (Ritalin) and amphetamine (Adderall) to cope with the well-known cognitive deficits associated with too little shut eye.

These drugs have legitimate uses: modafinil is indicated for treating daytime drowsiness associated with the sleep disorder narcolepsy; methylphenidate and amphetamine are stimulants used in attention-deficit/hyperactivity disorder (ADHD). But it is increasingly clear that their use has “crossed over from medical treatment to lifestyle enhancement,” Martha Farah, a University of Pennsylvania neuroscientist and expert on neuroethics, has pointed out.

For example, a 2005 survey by Sean McCabe and colleagues at the University of Michigan found that up to 25 percent of students on some college campuses are taking stimulants for nonmedical uses, presumably as study aids.

A recent informal online poll of subscribers to the journal Nature also found high use among academics and scientists: one in five of the 1,400 respondents reported taking methylphenidate, modafinil or beta blockers such as propanolol (drugs used in cardiac conditions that also have an anti-anxiety effect) to improve concentration, focus or memory. Methylphenidate was the most popular, taken by nearly two-thirds of users, and nearly half had taken modafinil.

In today’s culture, having an extra cognitive “edge” is hard to resist. In a lecture at the 2007 Society for Neuroscience annual meeting, Farah linked the increasing use of performance-improving drugs to society’s propensity to value long workdays and high productivity. “There is an increasingly acute problem of how to stay competitive on the job, have a life and get some sleep too,” she said. “The perfect time management tool is more time.”

The problem arises when finding “more time” comes at the expense of sleep. To Robert Stickgold, a leading sleep researcher at Harvard University, there are clear cases of unavoidable sleep restriction—certain job situations, soldiers at war, sleep disorders—where “something like modafinil makes perfect sense.”

“The concern is when it becomes a method for avoiding sleep,” Stickgold says. He questions whether such drugs are “acting as true cognitive enhancers, or are they just masking the effects of sleep deprivation? Are people self-medicating for sleep loss?”

The Power of Sleep

Our culture, Stickgold suggests, tends to devalue sleep—to think of it as a waste of time. Such thinking ignores reams of evidence for the beneficial effects of sleep on cognitive performance and on many other physiological systems.

“There are lots of data showing that sleep stabilizes, strengthens and integrates memories, and that cognitive performance is enhanced after a good night’s sleep,” Stickgold says. His own research shows that sleep is essential to consolidating and enhancing memories formed the day before.

Not getting enough sleep makes it harder to pay attention and therefore to take in new information. The classic studies showing the effects of sleep deprivation, pioneered by University of Pennsylvania psychologist David Dinges, found that people who get less than eight hours of sleep experience pronounced cognitive and physiological deficits, including impairments in memory, decision-making and attention, that worsen in a linear fashion over time.

And the effects of sleep loss go well beyond the brain (see “Sleep Loss Affects More than the Brain,” BrainWork, September-October 2006). Immune function suffers as well. Metabolism is disrupted, and there is growing evidence for a link between sleeplessness and obesity. The body’s endocrine system is also thrown out of whack: stress hormones increase and glucose and insulin regulation is impaired. Type 2 diabetes and cardiac problems are among the conditions associated with inadequate sleep.

If people are misusing cognitive enhancers to overcome the brain effects of not getting enough sleep, Stickgold says, “they’re masking a problem that’s larger than what they’re fixing—and it’s not just about memory. If the drugs are making it palatable for people to drop down to, say, five hours of sleep per night, are they risking more disease? There are downsides that people tend to forget about because they are subtle and gradual.”

Trevor Robbins, who studies mechanisms of cognitive enhancement at the University of Cambridge, U.K., believes there is “some truth” to the argument that the cognitive effects of stimulants and modafinil are merely an indirect effect of their ability to maintain wakefulness and alertness. But, he adds, “Some of these drugs may improve cognition independently of any effect they have on keeping you from falling asleep.”

Robbins’s own research, published in Psychopharmacology in 2003, compared modafinil to a placebo in normal, healthy volunteers—people who were not sleep-deprived. He found improvements in working memory, planning ability, pattern recognition and inhibition of impulsive behaviors. “I think it may be a slight misconception to say [the drug] is just stopping sleepiness,” he says. “It’s doing something a bit extra.”

Cognition is Multi-Faceted

A bigger question, Robbins says, is how the kinds of cognitive improvements seen in carefully controlled laboratory studies relate to “real life.” “Cognition is not just one thing; there are lots of different systems involved,” he says. “It may be that if you improve some things significantly, you do so at the cost of something else. So you’re going to have to compute whether the particular situation you’re in [will benefit from] enhancement of that faculty, and whether you can get away with impairment in another faculty that is irrelevant to the task ahead.”

Most users of cognitive enhancers likely are not making this kind of analysis as they reach for the Ritalin—orcaffeine or an energy drink, for that matter—to get the boost they need to finish the assignment or meet the deadline. In many cases, what they may really need is a good night’s sleep.

“I would predict that three-quarters of Americans have forgotten what it feels like to be well-rested,” Stickgold says. “If they discovered it, they would say: ‘Whoa. That’s a cognitive enhancer.’ ”