Deborah Orr: People's perceptions of Britain's cannabis laws are as clear as skunk

I'm touched, really, by the infallibility some people are conferring on our legal system. Whole swaths of self-proclaimed and actual experts appear to believe that the dope smoking habits of the nation have been finely regulated, like a radio being tuned to Stoned FM, by the recent incremental change in the classification of cannabis. So persuasive have their arguments been that the Home Secretary, Charles Clarke, is rumoured to be ready to rescind the legislation that two years ago led to cannabis's reclassification from class B to class C.

Their position is an odd and contradictory one. While they maintain that the reclassification of cannabis has motivated huge numbers of people to change their habits, they claim also that this attitudinal sea change happened only because people didn't understand what was going on. They argue that people smoke cannabis because they believe the Government has, by making the legal penalty for possession of this illegal drug extremely slight, endorsed it as safe.

This, it is claimed, contradicts the research linking cannabis use to mental health problems including the very serious and often untreatable illness schizophrenia, that has been available for years. Though the research remains controversial, I believe it is convincing, especially when the onset of these symptoms is linked to skunk, the high-strength cannabis that in recent years came to dominate the market.

For the sake of formal accuracy, therefore, I'd be happy to see skunk and hash given different legal classifications. In fact, I think this would be more useful than a return to the situation we had previously, whereby the legal response to cannabis possession was often farcically out of proportion to the ubiquity of the misdemeanour that had been committed.

But that would not address the actual difficulty, which goes far beyond the level of illegality we confer upon certain substances. If campaigners are convinced that people smoke cannabis under the impression that it is safe, then how do they explain the national propensity for risky behaviour such as drinking and smoking that goes far beyond drug use, and had proved only partially amenable to health education campaigns?

People don't do any of this because they are under the impression that it is harmless. They do it for all sorts of reasons, from unhappiness to peer pressure, from compulsion to depression. They do it also because they think they are willing to take the risk that it will not happen to them.

This latter reason is significant because it is also the reason why so many people are untroubled by the idea of taking part in illegal acts that they perceive as being damaging only to themselves. (Not true, of course, since the international drug trade is so ruthless and pitiless.)

The truth is that our criminal justice system is so inefficient at apprehending criminals that making an example of those people they do catch taking part in such widespread activity is simply pointless and too cruel. People understand all of this perfectly well. So the Government can retune as carefully as it wants to. This won't change the fact that the transmitter isn't working.

* Now that poor old Charlie Kennedy has finally told the truth, everyone has started calling him a liar. I'm afraid that chastising an alcoholic for lying is like condemning a thrush for having a spotty chest. Denial is part of the addictive condition, and the fact that he had admitted to his problem means that Mr Kennedy is making progress with his recovery. Interestingly, there's a definite pattern whereby couples break up not when the addict is in the throes of his illness, but after he has addressed it, when the participants can stop firefighting and start looking to the future. Maybe it's the same with party leaderships.

The new, healthy diet that's impossible to work out

Foolishly, I bought Dr Gillian McKeith's diet book the other day. I've never see her telly show, nor paid her much attention. But I was in the health food shop, and the books were piled up by the cash register. On impulse I thought: "She's a doctor! And I'm in a health shop! This must be sensible!" Alas, no!

Ms McKeith, right, decries the "excuses" people make for not following her advice, such as having children to look after, or jobs to turn up to or a budget to live on, as totally unacceptable. "Just stop playing the blame game and start taking responsibility now," she advises. But she's the irresponsible one.

The "28-day food plan" she outlines in her book is quite impossible for anyone to do unless they have little else to focus on in their lives.

The recipes for the first two days alone include the following fresh ingredients (organic, of course): lemon, blueberries, raspberries, strawberries, celery, carrots, watercress, spinach, rocket, cherry tomatoes, cucumber, dill, yellow pepper, ginger, garlic, coriander, red pepper, beansprouts, bok choi, mango, peach, banana, grapes, little gem lettuce, avocado, fresh basil, bay, lemon grass, a kaffir lime leaf, tarragon, radishes and alfalfa sprouts.

I list fresh ingredients for two days, as I understand fruit and vegetables, if they are to maintain nutrients, can't be stored any longer than that.

This means that shopping three or four times a week takes up a huge chunk of time. And that's before you prepare it, do the 20 minutes of exercise that the Doc recommends before you eat it and make sure the children have something to eat.

I don't know about the rest of the population, but I would find it quite hard to get all those ingredients. And that's if I had no qualms about buying food out of season from abroad (which I do).

In other words, far from being healthy, Dr McKeith's diet is an ecological disaster that encourages British consumers to buy what they want when they want, regardless of the environmental price.

Oh, the glamour of it all

As I sat down to watch Celebrity Big Brother, I persuaded myself that even though the "normal" show had become extreme, it was OK to watch celebrities being exploited, because they'd brought it on themselves.

By the end of the programme, I was aware this was not going to cut the mustard. The people who have been gathered together for this show are truly afflicted and should not be mocked. Even the ones who appear normal, and they are few and far between, quickly start to sound mad. Faria Alam, she of the Football Association sex scandal, claims that being in the tabloids for three weeks running is the "most frightening and daunting thing that any human can experience".

Then there was the sight of Jodie Marsh, Pete Burns and Traci Bingham bonding. Theylooked so distorted they made flashy Chantelle, a promotions girl who is pretending to be the singer, look like a Quaker. In fact, her comparatively sensible presence makes you more uncomfortably aware that "celebrity" is just a modern word for "freak". I fear Chantelle is not going to find it glamorous being in a room with that lot. It might put her off glamour for life.