STUDENTS preparing for end-of-term exams are using a new generation of "smart drugs" such as Ritalin, which can boost brain activity and keep healthy adults awake for more than 36 hours at a time.
Experts have told The Scotsman that the use of such medication by young people - commonplace in the United States - is becoming an increasing cause for concern in Scotland.
The smart drugs, also known as nootropics, include a range of powerful prescription medications. But they can also be bought over the internet - about £8 for a month's supply - without a prescription.
The top three drugs are methylphenidate, marketed as Ritalin and prescribed for children as a treatment for attention deficit disorder (ADHD); Donepezil, used to help Alzheimer's, and Modafinil, used for chronic sleeping problems such as narcolepsy.
Experts say that the potential market for cognitive enhancers is huge, appealing to a range of people including professionals under pressure to perform in the workplace and shift workers wanting to control sleeping patterns, as well as students under pressure to do well in exams.
A survey of 119 colleges last year by the American College Health Association found on certain campuses that up to 25 per cent of respondents had misused ADHD medication.
A number of clinical studies have shown that such smart drugs can produce significant mental gains in normal, healthy subjects.
Donepezil has been found to boost the brain function of healthy people by increasing the concentration of a neurotransmitter called acetylcholine, boosting the power of certain electrical transmissions between brain cells.
But neuroscientists warn that the long-term effects on healthy people are difficult to predict. Over time, they might cause people to remember too much detail, cluttering the brain and making it difficult to shift attention to a new task.
Short-term effects can range from nausea and irritability to heart attacks in extreme cases.
Professor Neil McKeganey, from the centre for drug misuse research at the University of Glasgow, said: "The growing use of nootropics, or smart drugs, is a problem which people in the arena of drug usage are becoming increasingly concerned about.
"There is a growing perception among groups such as students that these drugs, which were developed for the clinical population, can be used to improve task performance and for exams."
John Arthur, manager of Crew 2000, the Edinburgh-based drug advice group, said his organisation and sister agencies across Europe had become aware of the trend for taking smart drugs, especially among students.
He said: "I think part of the reason for them taking these drugs is the pressure on them to succeed."
A spokesman from the Medicines and Healthcare Products Regulatory Authority warned against people taking prescription-only drugs unless prescribed by a GP.