Sandra is an air steward. She pops a tab every time she crosses the Atlantic to make sure she's perky on landing. Gerry uses them during exams to give his concentration a boost. Simon, a junior doctor, takes one during the night shift to keep sleep at bay and his brain sharp.

You won't find their pill of choice on the shelves of your local head shop but there's growing evidence that high-flying professionals and stressed-out students are relying on brain-boosting drugs to quicken their thinking and keep them awake.

This week in Britain, scientists urged the government to bring the closet phenomenon of so-called smart drugs into the open, claiming their use is spreading across all sectors of society from surgeons to soldiers.

Researchers from Cambridge University warned that the drugs, which were designed to help people with neurological disorders like attention-deficit hyperactivity disorder, Alzheimer's and brain injury, are now being used for reasons far beyond their original purpose by uptight executives, multi-tasking mothers and exhausted shift-workers who need a chemical pick-me-up.

No self-respecting GP would prescribe these powerful brain-changing drugs to a patient suffering from poor concentration or tiredness, so users are turning to the internet, where a multitude of websites offer them for sale.

In Ireland, customs officers are at the coalface of this new craze, with increasing quantities of cognitive-enhancement drugs such as Modafinil and Ritalin being shipped into the country illegally every year.

In 2008, 1,250 tablets of Modafinil, a sleep inhibitor, were seized at ports and airports, rising to 1,920 last year.

In the first two months of this year, 170 tablets were found. Seizures of Ritalin, dubbed 'kiddie cocaine' in the US where it is doled out like candy to school-going children, have been lower but significant all the same with more than 612 units found since 2007.

Here, Modafinil is sold under the trade name Provigil. In November, its manufacturers Cephalon were granted permission by the Irish Medicines Board to market the drug for the treatment of excessive daytime sleepiness associated with sleep apnoea.

Taoiseach Brian Cowen is among those who suffer from this condition, which periodically causes breathing to stop during sleep.

Originally developed in France, Modafinil, which is also licensed to treat narcolepsy -- a disorder marked by sudden uncontrollable attacks of daytime sleep -- is the first of a new generation of wake-promoting drugs which targets the sleep/wake centres in the brain. It works by activating sleep-suppressing neurons fooling the mind into believing it is time to be alert.

This pharmaceutical prototype has the power to keep a person awake and focussed for up to 90 hours running, without the jitteriness or poor concentration that other stimulants like amphetamines or caffeine are known to produce.

Proponents say it works without causing a crash after its effects have worn off and does not create any sense of euphoria in the brain thereby limiting its potential for abuse.

The use of Modafinil within the American military is well-documented where it has been approved for use on air force missions, allowing troops to stay awake for days at a time and complete operations as quickly as possible.

In Britain, the drug was approved for use in 2002, and since then has surged in popularity. The number of prescriptions for stimulants like it has nearly doubled in recent years, rising from 458,000 in 2004 to 751,000 in 2008. A Nature magazine poll of 1,400 respondents, mostly scientists and academics, suggested that one in five had used 'smart drugs'.

Fears that stay-awake pills are increasingly being used as 'lifestyle drugs' are strengthening, especially since their long-term effects on the brain are still unknown.

Some neuroscientists also worry that drugs like this will turn humans into mechanistic beings who pop a pill when they need a brain boost rather than opting for a brisk walk or a good night's sleep.

Pharmaceutical advances like this could make cosmetic neurology as popular as beauty enhancements, they claim. And there are ethical concerns about the unfair advantage such drugs give to users over their peers in academic settings. In the US, surveys show that an estimated 16-20pc of US college students take smart drugs to help their memory and keep them alert. The drugs may especially help in subjects like mathematics and science by aiding students to complete puzzles and remember long chains of digits.

Last week, one of Britain's leading psychologists called for an official university-wide strategy to tackle student misuse of prescription drugs like Modafinil.

Barbara Sahakian, professor of clinical neuropsychology at Cambridge University, whose work is at the forefront of research into cognitive enhancement drugs, has even raised the prospect of dope testing of exam students as a possible safeguard against their use.

"This is something that universities really have to discuss," she says.

"It has enormous implications. The coercion aspect is a strong one. Some students say they feel it is cheating and it puts pressure on them to feel they have to use drugs when they don't really want to.

"You have to consider there are things that could be beneficial about such drugs because we have an ageing population: people will have to work for longer and their pensions may not be performing.

"The big question is, are we all going to be taking drugs in the next 10 years and boosting our brain power in this way? And if we are, will we use them to have a shorter working week, so we can go home, spend more time with our families and have a good work/life balance? Or will we go headlong into a 24/7 society were we work all the time because we can work all the time?"

Improving brain power and its ability to stay awake is certainly where drug companies think the future lies as the market for treatments for neurological and psychiatric illnesses continues to outstrip that for painkillers and cardiovascular drugs in the western world.

Dozens of neuro-enhancing drugs are currently in the research pipeline and their use in the coming years is expected to soar.

Advocates argue that smart drugs will remove disparities in society and give those who are mentally challenged a better chance of self-improvement and success.

They also claim it is better for high-risk professionals like surgeons and pilots to take a medically-controlled tablet rather than dosing themselves up on caffeine and ending up with a shaky hand and a twitchy disposition But for those dealing with the downside of chemical consumption, the advent of smart drugs is a worrying prospect.

"As with any stimulant that alters the central nervous system, you have to stop and think of the long-term consequences of using these drugs," says Dr Fiona Weldon, clinical director of the Rutland Centre, Dublin's leading addiction therapy centre.

"We are unsure about the extent to which these drugs are being used in Ireland but it would be naive to think it isn't happening and it is something we should be very worried about," she says.

"I've seen students become reliant on the likes of Ritalin. They claim it makes them work better but before you know it there is a dependency.

"There is such a tendency now to seek out a quick chemical fix as the solution to our stresses but if you over-stimulate the brain in a false way, the system will eventually crash and the side effects are incredible."

Irish Independent