Professor Steven Rose warned the conference in Birmingham that we are moving inexorably to the world "envisaged by Aldous Huxley in his novel Brave New World", in which people took the drug soma to find tranquillity. Professor Rose fears that in our world there will be a far wider range of pharmaceutical drugs able to have all sorts of effects - many of them only dimly understood - on the brain.
"We need to look more closely at the border between legal and illegal drugs," he said. "The borderline is not absolute - it depends on society," said Professor Rose, a neuroscientist who is head of biology at the Open University.
Particularly worrying was the widespread use in the United States of ritalin, an amphetamine like drug which is now prescribed to roughly 10 per cent of male US children who are diagnosed as having "attention deficit syndrome" because they misbehave.
"That troubles me, yet it is acceptable," Professor Rose said. "But recreational drugs cause great moral outrage."
Yet, he said, heroin was legal in the 19th century, and Coca-Cola used to contain cocaine.
Susan Greenfield, of Oxford University, who is also a specialist in brain function, said: "There is a perception that any particular molecule used as a drug has a built-in function, and it only affects a particular neural network in the brain. But when you take a drug - whether prescription or otherwise - it marinates the brain in that chemical. Your brain is not then working as normal."
Prozac, a prescription drug, has been implicated in unusual behaviour. In one case in the US, a depressive who had been taking Prozac ran amok with a gun and killed a number of his colleagues. The effects that ecstasy has on the brain and body are poorly understood, partly because it is not possible to carry out controlled trials because it is illegal.
At the start of a three-day session on brains, minds and consciousness, Professor Rose argued that "we are at a point in history where, probably for the first time, neuroscience is confronting public policy."
A growing number of scientists suggest that genes determine brain function - leading to what Professor Rose calls "neurogenetics". He says thisidea is misleading and leads people to believe that such disorders as violence, alcoholism, compulsive shoppingand homelessness cannot be cured by social means. Instead, they seek to develop drugs as therapy, moving towards Huxley's vision.
Instead, he said the science needs theories to connect molecular biology - which can now picture and analyse brain activity at the level of nerve cells - with psychology, which analyses social interactions. "We have the technological tool box, but we lack overarching theories of the brain to put the lot together," Professor Rose said.Reuse content