'Smart drug' claims rejected

So-called 'smart drugs', which allegedly enhance people's mental abilities, only work in people whose brain function is impaired, scientists told a conference in Cambridge yesterday.

In California, 'smart bars' have opened where people can drop in and consume cocktails containing 'cognition enhancers' - compounds which are supposed to boost the drinker's brain-power.

However, results from clinical studies suggest that the people who claim to have their mental faculties improved by smart drugs must have been cerebrally impaired in the first place. The drugs may be able to restore a deficit, but do not enhance normal function, speakers at the annual conference of the British Association for Psychopharmacology said.

Old people whose memories are faulty appear to be responding to treatment with a drug which interferes with the action of a molecular messenger within the brain, known as serotonin. The conference was told that a serotonin blocking drug, known as ondansetron, has shown promising results in clinical trials.

However, the researchers could not detect any improvement in the performance of young people with unimpaired memories. Dr Gilbert Clincke, of the Belgian pharmaceutical company, Janssen, told the conference: 'More than 130 compounds have been claimed to be cognition enhancers, but none have been shown to be clinically effective (in normal people).'

Nicotine improves some aspects of Alzheimer's disease, such as attention or concentration, Dr Barbara Sahakian from the psychology department at Cambridge University reported. But, in a complex series of cognitive tests, nicotine did not improve the short-term memory of Alzheimer's sufferers.

Even if 'smart drugs' did work, they might face difficulties in getting approval from regulators, Dr Paul Leber, of the United States government's Food and Drug Administration, said.