Is ‘brain doping’ a bust? Studies question drugs’ benefits

Enhancing cognitive performance with off-label prescriptions of psych drugs like modafinil and methylphenidate is increasingly popular on college campuses and Wall Street, where users pop the pills as study aids or to gain a competitive edge.

Two of the most popular purported enhancers are methylphenidate, a stimulant that was approved for treatment of attention deficit hyperactivity disorder (ADHD), and the anti-narcolepsy drug modafinil.  Modafinil is now prescribed by the U.S. Air Force as the new “go pill” alternative to amphetamines to counter pilot fatigue.

A 2008 poll of 1,400 readers of the science journal Nature found that 20 percent were using these drugs or beta blockers for non-medical reasons — primarily to improve concentration and alleviate fatigue.

But now, results from the German government-funded “Potentials and Risks of Psychopharmaceutical Enhancement” research program suggest the real-world effects of brain doping don’t live up to much-hyped expectations.

In the first of two systematic reviews, the team analyzed data from 46 studies of methylphenidate neuroenhancement — and concluded that contrary to rumor, it does not boost attention, vigilance or focus.  Most studies found either no effect or negative effects such as disruption of attention span, the authors report.

There was modest evidence for short-term spatial memory benefits, the team found – promising indeed for lab rats confronting a daunting maze.

For modafinil, data from 45 studies found modest evidence of benefits for attention — but not memory, mood or focus, the authors report.

So why do so many intelligent people, including a sizable proportion of Nature readers, shell out their hard-earned money for an apparently illusory brain boost?

In the case of modafinil, at least, the answer may be drug-induced overconfidence.  Particularly among sleep-deprived users, overconfidence is common.  Study participants taking modafinil consistently overestimated their performance on just-completed cognitive tests.

A military study found no such effect.

“Nevertheless, it remains a question of great importance,” the authors report, suggesting modafinil may “interfere” with accurate self-assessment.

A single modafinil dose does seem to alleviate moderate sleep deprivation, the authors found.   Repeated doses maintain wakefulness in the face of sleep deprivation, but not other measures of cognitive performance.

In a previous review of data from the scant literature on off-label neuroenhancement using anti-dementia drugs like memantine and acetylcholinesterase inhibitors (donepezil, galantamine and rivastigmine), the team came to similarly disappointing conclusions.

“At the moment, the research that would support or oppose the use of acetylcholinesterase inhibitors and memantine for neuroenhancement by healthy individuals has not yet been performed,” they concluded.

The authors did not include a conflict-of-interest statement in the published studies.  The research was funded by the German Federal Ministry of Education and Research, grant 01GP065.

Modifinil is marketed under the brand names Provigil, Alertec, Modavigil, Modalert, Modiodal, Modafinilo and Carim.

Further reading: