Increasing use of ''smart drugs'' among students aiming to improve their memory and cognitive function could prompt authorities to start drug-testing students before exams, an Australian researcher says. Vince Cakic, a researcher from the University of Sydney's school of psychology, said in an article published in The Age today, students were increasingly using psychostimulants - drugs usually prescribed for neuropsychiatric disorders and sleep disorders - to enhance their academic performance.

He said drugs such as selegiline, usually prescribed for Parkinson's disease, were touted as a motivation enhancer, while others, such as modafinil and piracetam, were known for keeping people alert and improving their memory respectively.

Internationals students are often under high pressure to perform, as their family back home safes all the money they earn to let the student go to College or University. This group of studetns could be particular vulnerable to the promisses Smart Drugs seem to offer.

Collectively, the drugs are known as ''nootropics'' or ''smart drugs'', he said, because of the Greek words noo (mind) and troppo (to turn or change).

Mr Cakic said it was particularly popular among students because it kept them awake and alert without making them hyperactive. Research recently published in the US suggested modafinil was addictive.

''I would say a lot of students are using that now,'' Mr Cakic said. ''Memory enhancers like piracetam are also very popular.'' Mr Cakic said the drugs were easily purchased over the internet through online pharmacies in South-East Asia, Mexico and India, but he said amphetamines such as Dexedrine were harder to buy because they were controlled substances.

In an article published in the Journal of Medical Ethics today, Mr Cakic said although some of the drugs had well-known side effects, including addictive qualities and the potential to aggravate mental illness, it was unclear how dangerous most of them were for healthy people long term.

''It remains to be seen whether nootropics represent a pharmacological 'free lunch' or if the enhancement of some cognitive functions can only be realised at the expense of others,'' he wrote.

Mr Cakic said increasing use among students could prompt people to treat them like performance-enhancing drugs in professional sport. If it was perceived they offered students an unfair advantage, drug tests could follow.

Australian Drug Foundation chief executive John Rogerson said anecdotal reports suggested young people were talking more about these drugs, but he said there was no indication it was a big problem in Australia.

''We haven't got evidence of this, but there's no doubt that kids are taking stimulants like Ritalin to get a short-term advantage,'' he said. ''We would encourage young people to stay away from it.''