Ritalin is used to treat hyperactive children
There are fears a growing number of students are turning to a stimulant drug used to treat hyperactive children to enhance their academic performance.
Researchers in the United States found Ritalin, an amphetamine-based drug, is fast rivalling more traditional stimulants like caffeine and cigarettes as students battle with essay deadlines and exam stress.
With recent concerns about children in Scotland selling the drug to dealers or swapping it for CDs and phone cards, drug agencies say universities in the UK should be aware that the drug could be available on the black market.
Ritalin, usually prescribed for children with attention deficit hyperactivity disorder or ADHD, is a mild stimulant that works on the central nervous system to improve concentration.
Researchers from the University of Michigan believe more must be done to tackle the growing problem of students getting hold of the drug.
"Illicit use of prescription-only stimulants on college campuses is a potentially serious public health issue," their report concluded.
"More work is needed to promote understanding and awareness of this problem among clinicians and researchers."
The use of the drug Ritalin has proved controversial in the UK.
Last year, parents in Scotland staged a protest outside parliament, saying there were better non-drug treatments available for children who suffer from ADHD.
Critics have raised concerns about the increasing number of children being given the drug.
According to the Department of Health, the number of Ritalin prescriptions in England last year was 254,000.
This represents more than double the 126,600 made out in 1998.