Leading article: This is no occasion to panic

There is a flicker of moral panic in the air when it comes to the debate on whether or not to reverse the move which two years ago downgraded the criminal status of cannabis. That change was a sensible one. It reflected both a shifting a social consensus and the balance of medical opinion as to the harmfulness of the drug.

Suddenly it's all change. The populist press is in full cry, quoting the warning by the Royal College of Psychiatrists that a "wealth of research evidence" exists linking cannabis with long-term mental disorders and violence. So there is. But the pertinent question is: what has changed?

What has changed is the politics. The Government's critics in the press sense a new subject on which to attack this beleaguered administration. New Labour strategists are increasingly cagey about the possibility that they may be about to be wrong-footed by the Conservative Party which seems, under David Cameron, to be adopting a more mature line on cannabis. The Government fears being caught between the devil and deep blue press on this one.

They should hold their nerve. For the evidence is with their initial instinct. All drugs have side-effects and it is true that schizophrenia is between two and four times more common among dope-smokers than in the rest of the population.

But set that in context. It still means that at least 96 per cent of users will be perfectly safe. Compare that with alcohol, or with tobacco which harms everyone who uses it.

The Home Secretary this week conceded that we still don't know a lot about the relationship between cannabis and mental health. The association between the drug and psychosis may not be causal; it may simply be, for example, that people who are in the early stages of mental illness are more likely to turn to drugs.

There are grounds for further research. But there are not, at present, grounds for a further reclassification.

The arguments which were persuasive when cannabis was downgraded two years ago still apply. The police need to focus on tackling harder drugs such as heroin and crack. They need to be freed up to fight serious crime.

We must not be complacent about the dangers. The cannabis on the streets is stronger today than it was before, and it is being used by younger people, who are more susceptible to its ill effects.

However, the evidence is that cannabis consumption has declined over the last two years. What that suggests is that we need yet more education to alert more people to the problems. But we do not need to fiddle with the law.