Do 'smart drugs' really make us brainier?
"One pill. Anything is possible." That's the message advertising Limitless, a film showing in cinemas this week.
Starring Bradley Cooper and Robert de Niro, the film tells the story of a writer who takes an experimental drug that allows him to use 100% of his mind.
Success, fame and a much-improved hairdo follow. The designer pharmaceutical turns him from being disorganised and unmotivated into someone laser-focused and more confident than any man alive.
But is there any truth in the scenario? Can a little pill impart limitless brain power?
Drugs like the one portrayed in the film do exist and they have been found to boost concentration and improve memory, hence the use of the term "smart drugs" to describe them.
Modafinil has been branded a smart drug because of its growing use among UK students to cope with the fatigue of exams.
Although it was originally designed to treat narcolepsy - extreme drowsiness and sleep disorders - its ability to increase levels of wakefulness and alertness has given it popularity among a number of groups.
It has been used by the military to keep soldiers awake in times of combat and its use is thought to be on the rise among shift workers, such as nurses, doctors and pilots. Modafinil is also said to be popular among jet-lagged academics.
Research by Barbara Sahakian, professor of clinical neuropsychology at Cambridge University, found that 17% of students in some US universities admitted using the stimulant Ritalin (methylphenidate) - a drug designed to treat hyperactive children - to maximise their learning power.
A survey of 1,400 adults carried out by Nature found that one in five said they had taken Ritalin, Provigil (modafinil) or beta-blockers to stimulate focus, concentration or memory - not for any medical condition.
Professor Sahakian explained what the benefits of the drugs are on healthy people: "Studies have found that enhancers like modafinil brought improvements in complex planning and problem-solving tasks, namely the executive functions in the front part of the brain."
"Modafinil has also been shown to improve memory functions and Ritalin has been shown to specifically improve working memory."
But scientists still do not know exactly how the drug acts in the brain to boost cognition.
Better than coffee?
So it is no real surprise that the use of smart drugs is on the increase. It is an attractive proposition - becoming as alert and efficient as we have the potential to be, when we need to be.
Even if they improve memory function by just 10%, which has been suggested, it could be the difference between passing and failing an exam, between a good grade and a better one.
"Students will feel pressure over whether to keep up with their peers if they are using these drugs," says Prof Sahakian.
But do these little pills do anything more than caffeine?
Professor John Harris, director of the Institute for Science, Ethics and Innovation at the University of Manchester, says they give people an edge.
"They have a similar effect to hard work and coffee. Physical exercise also has the same effect. They are all, to an extent, cognitive enhancers."
Taking Modafinil may help people do tiring jobs but it will not turn anyone into Albert Einstein overnight.
"If you're not a genius before, you won't be afterwards. They don't make you brainier," says Prof Harris.
Yet it is still not clear how safe these cognitive enhancers are.
The long-term implications of taking smart drugs have not been studied, principally because no-one is sure who is using them as "neuroenhancers".
They are only available via the internet for this purpose and so it is difficult to know how many users exist.
The charity DrugScope warns of the risks of buying pills this way.
"You can never be fully aware of what you are buying, you can't know what's in them or what adverse reactions they might cause or how they fit with other drugs you might be taking," says a DrugScope spokesman.
And then there is the issue of how addictive they might be.
Although Modafinil is not thought to be addictive, DrugScope has concerns that regular use of any drug can lead to dependency.
The charity advises anyone taking anything known as a smart drug to consult their GP first.
What Prof Sahakian would like to see is a formal policy on smart drugs.
"The government should consider the harms of cognitive enhancers and address them," she said. "Universities need policies on the use of these drugs, guidance on what is acceptable and what is not."
Until then, people will keep taking them to pass their exams and to stop getting tired, because they can.
The ethics of taking smart drugs have often been debated.
Those in favour of making cognitive enhancers available for non-medical use say they are no different to exercise and learning in the way they shape our brains.
If they are a quick fix which helps us function better in our daily lives, then what is the issue?
Others say there is no such thing as a safe drug.
There are potential side effects and the risks for a young person taking them over a long period is unknown.
Internet pharmacies are also a very risky and unregulated source.
Limitless brain power may be attractive but, as the film shows, there are always risks and complications.